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THE 

F  A  R  M  E  R'S 

LIGHTHOUSE. 


CHEMIS^B'Y;  V  ,     0 

,  •  ^ 

A  P  P  L  I^,S  ,"^V*        ^  '  '    \     *   ' '  '    '  •  « 
THE  ONLY  PROFITABLE  MODE  OP 

TILLING     THE     SOIL. 
BtJ.  B.  K^BNT,  A.M.,M.D., 

Professor  of  Materia  Medioa  and  Therapeutics  in  the  Penn 
Medical  TTniversity  of  Philadelphia,  etc. 


BOSTON: 

HIGGINS    AND    BRADLEY, 

20  Washington  Stbeet. 

1856. 


K45 


•  •     •«•••  •       t, 

•   •  •  ♦  •       • 


f^Tf^i^ 


Batered  according  to  Act  of  Congress,  in  tbe  year  1855,  by 

HiaaiNS    AND    BRADLEY, 

In  tbe  Clerk's  Office  of  the  District  Court  of  the  Soatheru  District 
of  New  York. 


CONTENTS. 


PAGB 

Application  of  manures  to  the  soil, 50 

Animal  manures, 52 

Ammonia  produced  by  fermentation  of  manures,    ....  61 

Ammonia  easily  detected  in  manures,  ...       ....  61 

Ammonia  abundant  in  the  urine  of  the  cow  —  its  preser- 

Tation  important, 63 

Ammoniacal  liquor  of  gas  works  as  a  manure, 64 

Apples  as  food  for  stock, 84 

Appendix, 87 

Analysis  of  urine, (A.  28)   .    .  97 

Analysis  of  stable  manure, (A.  29)  .    .  98 

Blood  as  a  manure, 53 

Bones  as  a  manure, 53 

Bones  as  a  manure  on  dairy  lands, 55 

Bones,  how  prepared  as  manure, 56 

Best  time  for  the  application  of  saline  manures,    ....  69 

Constituent  nature  of  the  productions  of  the  soil,  ....  14 

Carbon, 15 

Chlorine, 24 

Carbonic  acid  gas, 28 

Composition  of  substances  in  the  structure  of  plants,     .   .  31 

Composition  of  water, 33 

Composition  of  starch, 34 

Composition  of  gluten, 35 

Causes  of  good  lands  being  unproductive,  and  the  remedy,  46 


C6T8 


►•V. 


IV  CONTENTS. 

PAGS 

Composition  of  bones, 54 

Composition  of  ammonia, 62 

Common  salt  as  a  manure, 68 

Composition  of  crops, 76 

Composition  of  sugar, 78 

Caxbon,  quantity  thrown  from  the  lungs  of  a  man  daily,  .  78 

Chlorine,  how  made, (A.  12)  .    .  90 

Carbonic  acid  gas,  how  macks,, (A.  15)  .    .  92 

Construction  of  drains,     .'V (A.  26)  .    .  96 

Composition  of  urine, (A.  28)  .    .  97 

Chemical  symbols, (A.  30)  .    .  99 

Chemical  equivalents, (A.  31)  .   .  99 

Combinations  of  nitrogen  and  oxygen,     .    .    .  (A.  33)  .    .100 
Combinations  of  manganese  and  oxygen,     .    .  (A.  34)  .    .  101 
Composition   of  starch,   gum   and  sugar,  almost   identi- 
cal,  (A.  37)  ..  104 

Description  of  the  gases, 18 

Difference  in  the  ashes  of  plants, 26 

Distinction  between  organic  and  inorganic  substances,     .  35 

DiSference  in  soils, 38 

Difference  in  light  and  heavy  lands, 39 

Depth  of  drains, 40 

Difference  in  the  dung  of  animals  and  the  food  they  con- 
sume,   59 

Diamond  and  charcoal  chemically  identical,    .  (A.  2)  .    .  8-7 

Division  of  food  into  two  classes, (A.  47)  .    .  106 

Elementary  substances, 15 

Excrement  of  birds  as  a  manure, 64 

Elementary  and  compound  bodies,     ....   (A.  20)   .    .  93 
Explanation  of  the  phrases  by  which  salines  are  contra- 
distinguished,     (A.  24) .   .  95 

Food  of  plants, 26 

Food  of  plants  —  its  sources, 27 

Flesh  as  a  manure, •   .    .  53 

Fish  as  a  manure, 66 


CONTENTS.  V 

PAGB 

Food  of  animals  must  contain  starch  (carbon), 78 

Food  rich  in  fatty  matter  soonest  fattens  stock, 81 

Food  of  cattle  should  be  sweet, .  84 

Food  of  hogs  best  soured, 84 

Food  requisite  to  keep  a  horse  in  good  condition,  (A.  45)  106 

Food  of  hogs,  its  diflferent  results, (A.  46)  .   ,  1©6 

Gluten, 31 

Gelatine  of  bones  as  a  manure, 65 

Guano  for  turnips  and  potatoes, , 66 

Guano  for  grain  and  corn  crops, 66 

Gypsum, 69 

Gluten  essential  as  a  part  of  the  food  of  animals,  ....  80 
Growing  animals  and  full-grown  ones  require   different 

food, 81 

Gluten,  how  separated  from  flour, (A.  18)   .   .  93 

Hydrogen, 15 

Heavy  or  clay  lands,  how  made  to  yield  profitable  crops,  41 

Hair  as  a  manure, 57 

Hydrogen  gas,  how  made, (A.  3)  .   .  87 

Humic  acid,  how  formed, (A.  17)  .   ,  92 

Introduction, 9 

Iron, 22 

Importance  of  organic  matter  in  the  soil, 36 

Importance  of  drains,   .   .    • 39 

Inorganic  food  of  plants, 41 

Inorganic  substances  essential  for  the  growth  of  plants,  .  42 

Importance  of  rotation  of  crops, 47 

Knowledge  essential  to  the  farmer, 14 

Kelp  as  a  manure, 70 

Lime, ,  21 

Limestone,  its  varieties, 71 

Lime,  what  lands  most  improved  by  it, 71 

Lime,  how  detected  in  land, 72 

Lime  as  a  manure,  how  and  when  applied, 76 

Law  of  chemical  combinations, (A.  32)  .   .  100 

1* 


VI  CONTENTS. 

TAQM 

Magnesia, 22 

Manures,  use  of,     ....            49 

Manures,  three  kinds, 50 

Manures,  vegetable, 51 

Manure  tank,  its  value, €3 

Manures,  mineral,      67 

Manure  made  by  fattening  stock  more  valuable  than  that 

by  growing  stock, 82 

Mode  of  making  the  most  beef  or  mutton  from  a  given 

weight  of  food, 82 

Milk,  how  obtained  in  the  largest  quantity, 83 

Milk,  how  obtained  of  the  best  quality, 83 

Milk,  designed  lor  butter, 83 

Milk,  designed  for  cheese, 84 

Nitrogen, 18 

Non-azotized  substa.ices, 19 

Night-soil  the  most  valuable  manure, 58 

Nitrogen  of  manures  changed  into  ammonia,  ,,,...  61 

Nitrate  of  soda,  .  ■ 67 

Nitrogen  gas,  how  made, (A.  5)  .    .  88 

Nitrogenized  or  nutritious  elements,    .    .    .    (A.  47)    .    .  106 

Non-nitrogenized,  or  elements  of  respiration,  (A.  48)    .   .  100 

Object  of  the  farmer, 13 

Oxygen, 17 

Oxide  of  iron, 23 

Oxide  of  manganese, 23 

Oxygen  gas,  how  made,    .    , (A.  4)  .   .  87 

Oxidation, (A.  11)  .    .  89 

Proportion  of  organic  and  inorganic  matter  in  vegetable 

substances, 15 

Potash, 20 

Phosphoric  acid, 25 

Proof  that  plants  take  up  carbon  and  give  out  oxygen,  .  29 
Proof  that  water  contains  only  hydrogen  and  oxygen  gases,  34 

Productive  and  barren  lands, 45 


CONTENTS.  VII 

PAGB 

Poudrette  and  guano  as  manures, 58 

Prevention  of  the  loss  of  ammonia  from  manures,  .   .   .   .  6r 

Productions  of  the  soil,  their  use, 78 

Phosphate  of  lime  essential  in  the  food  of  animals,   .   .   .  81 

Phosphoric  acid,  how  formed, (A.  14)  .   .  91 

Quantity  of  bone-earth  in  ten  gallons  of  milk,    .    •  .    .   .  56 
Quick-lime  should  not  be  mixed  with  guano  or  manures 

containing  ammonia, 65 

Quick  or  caustic  lime, 73 

Quick-lime  changed  to  the  mild  carbonate  by  exposure  to 

the  atmospheric  air, 73 

Quantity  of  starch,  or  its  equivalent,  man  must  daily  con- 
sume, to  maintain  health, 79 

Relative  amount  of  carbon  in  flesh  and  starch,  ,  (A.  40)  .  105 

Source  of  the  subsistence  of  animal  life, 13 

Substances  found  in  the  inorganic  part  of  plants,  ....  19 

Soda, 20 

Silicia, 24 

Sulphuric  acid, 24 

Substances  in  the  structure  of  plants, 30 

Starch, 30 

Sources  of  carbonic  acid  gas, 32 

Substances  of  which  soil  is  formed, 35 

Sources  from  whence  the  organic  part  of  soil  is  obtained,  36 

Soil,  how  exhausted, 37 

Soil  supplied  with  organic  matter, 37 

Sources  of  the  inorganic  part  of  the  soil, 38 

Sources  of  the  inorganic  food  of  plants, 42 

Sulphate  of  soda, 68 

Salines  as  manures  improved  by  mixture, 70 

Slaked  lime, 70 

Solution, (A.  22)  .   .  94 

Symbols  and  equivalents  of  elementary  bodies  referred  to 

in  this  work, (A.  35)    .  .  101 

Table  of  the  ashes  of  grasses, .43 


VIII  CONTENTS. 

PAOl 

Table  of  the  composition  of  soil  naturally  fertile,  arti- 
ficially fertilized,  and  barren, 45 

Table  of  inorganic  substances  in  wheat,  oats,  barley,  and 
rye, 47 

Tables  of  symbols  of  the  principal  compound  bodies  named 
in  this  work, (A.  36)  ..  102 

Tribe  of  hunters  cannot  multiply  beyond  a  fixed  and 
early  attained  point, (A.  30)  .    .  104 

Use  of  ammonia  to  plants, G2 

Use  of  the  carbonic  acid  gas  thrown  into  the  atmosphere 
by  respiration, 79 

Woollen  rags  as  a  manure, 58 

Warmth  and  ventilation  important  to  stock,  and  a  source 
of  economy  to  the  farmer,. 85 


TO  THE  HEADER. 


The  Lighthouse  of  Agricultural  Chemistry  is  now  be- 
fore you,  treating  upon  one  of  the  most  important  occu- 
pations in  the  world — upon  the  products  of  which  all 
are  equally  dependent  —  the  manufacturer,  the  mer- 
chant, the  mariner,  the  politician,  the  statesman,  and 
mechanic,  alike  resort  to  our  mother  earth.  We  begin 
to  find  that  the  great  question  of  the  day,  in  all  our  large 
commercial  cities,  is  not  so  much  upon  stocks  in  ex- 
change, as  upon  the  probable  state  of  the  crops  this 
season.  Therefore  it  may  well  be  said,  he  who  makes 
two  blades  of  grass  to  grow  where  but  one  blade  grew 
before,  is  a  benefactor  to  mankind.  This  is  the  work  of 
agricultural  chemistry  to  perform ;  and  Tvithout  this  chem- 
ical knowledge,  the  lands  of  the  farmer  will  soon  become 
unproductive,   notwithstanding  it  may  be  highly  ma- 


11  INTRODUCTION. 

nured,  and  laboriously  worked.  Still,  in  addition  tu 
being  a  practical  man,  in  order  to  be  a  successful  farmer 
he  must  understand  in  a  measure  the  nature  of  the  crops 
he  raises,  the  character  and  constituents  of  the  soil  on 
which  they  are  grown,  and  the  different  kinds  of  ma- 
nures and  compost  most  suitable  to  prevent  exhaustion 
of  diiFerent  kinds  of  land ;  thereby,  with  the  aid  of  ag- 
ricultural chemistry,  the  wealth  of  the  United  States 
could  be  doubled  in  one  year,  were  all  that  saved  which 
is  now  lost  by  bad  management.  In  short,  the  wealth 
of  all  nations  depends  upon  the  rising  generation  of  prac- 
tical, chemical  farmers,  who  will  till  the  soil  as  much  by 
the  laws  of  chemistry  as  by  the  sweat  of  the  brow ;  and 
the  simple  facts  and  information  contained  in  this  little 
volume,  (for  only  thirty- three  cents,)  cannot  be  estimated 
in  dollars  and  cents,  and  should  be  in  the  hands  of  every 
man  in  this  country  as  a  book  of  reference,  even  if  he 
improves  nothing  more  than  a  garden  spot  of  twenty- 
five  feet  square. 

H.  &  B. 


THE 

FARMER'S 


Man,  and  the  varied  tribes  of  animal  life, 
derive  their  subsistence  from  the  earth.  Almost 
all  its  productions  grow  spontaneously,  but  nearly 
all  of  those  productions  may  be  greatly  improved 
by  appropriate  cultivation.  The  cultivation  of 
the  soil  is  called  agriculture,  and  the  cultivator 
is  an  agriculturist,  or  farmer. 

The  farmer  has  two  ends  to  attain:  1.  To 
improve,  by  cultivation,  the  natural  products  of 
the  soil ;  and,  2.  To  secure  the  largest  crops  at 
the  smallest  cost,  with  the  greatest  saving  of 
labor,  and  with  the  least  injury  to  the  land. 

Questions.  —  From  whence  do  man  and  animals  derive 
their  subsistence  ?  What  is  agriculture  ?  What  is  a  culti- 
v^ator  of  the  soil  called  ? 

2 


14  CHEMISTRY,    GEOLOGY 

To  insure  these  very  desirable  results,  the 
farmer  should  know  the  nature  of  the  crops  he 
raises,  the  character  and  constituents  of  the  soil 
on  which  they  are  grown,  and  the  manures  most 
suitable  to  prevent  exhaustion  of  the  land ;  and 
unless  he^.  possesses,,  >o.  5p?ie  , practical  extent, 
these  several  kinds  of  knowledge,  he  can  never 
becomf/§L•^^C^esgftli'ailcl;  pibfii^ble:  cultivator  of 
a  farm.  '  Without  this  knowledge,  his  land  will 
soon  become  unproductive  and  non-remunerative, 
notwithstanding  it  may  be  frequently  manured 
and  laboriously  worked.  This  knowledge  is 
called  Agricultural  Chemistry. 

THE    CONSTITUENT    NATURE    OF   THE   PRODUC- 
TIONS   OF   THE   SOIL. 

All  forms  of  vegetable  existences,  all  the  pro- 
ductions of  the  earth,  consist  of  two  parts,  or- 
ganic and  inorganic  matter;  the  organic  part, 
if  put  into  the  fire,  burns  away,  —  the  inorganic 
part  cannot  be  burned  up.     (See  Appendix,  1.) 

Questions.  —  What  onght  the  farmer  to  know,  in  order 
Buccessfully  and  profitably  to  cultivate  the  soil  ?  What  is 
this  knowledge  called  ?  Of  what  kinds  of  matter  do  Tege- 
table  productions  consist?  Which  part  is  combustible? 
Which  will  not  burn  away  ?  W^hat  is  the  part  called  which 
burns  ?     What  that  which  will  not  burn  ? 


AND   AGRICULTURE. 


15 


In   all   vegetable   substances,  ^^^•^• 

the  organic  or  combustible  part 
is  very  mucli  the  largest ;  it 
makes  from  ninety  to  ninety- 
nine  parts  out  of  every  hundred 
of  their  weight. 

The  organic  parts  of  all  vege- 
table substances  consist  of  four 
elements;  these  elements  are 
called  carbon,  hydrogen,  oxygen, 
and  nitrogen :  they  are  called 
elements,  or  elementary  bodies,  because  they 
have  never  yet  been  divided  or  decomposed. 

CARBON  is  a  solid  substance,  generally  of  a 
black  color ;  it  has  no  taste  or  smell ;  usually 
burns,  very  rapidly,  and  gives  out*  much  heat. 
Common  charcoal,  coke, —  the  substance  left  in 
retorts  after  the  gas  has  been  distilled  from  the 
coal,  —  lamp-black,  black-lead,  and  the  costly 
and  brilliant  diamond,  are  only  different  varieties 
of  carbon. 

HYDROGEN  is  found  only  in  the  form  of  a 

Questions.  —  Of  which  do  vegetables  contain  the  most? 
State  the  proportions.  Of  what  is  the  organic  part  of 
plants  composed  ?  Why  are  they  called  elementary  bodies : 
What  is  carbon  ?  Name  some  of  its  varieties.  What  \a 
hydrogen  ? 


16 


CHEMISTRY,    GEOLOGY 


gas,  or  of  a  kind  of  air.     It  burns  as  coal-gas 
doeS;  but  its  flame  is  blue,  and  gives  a  very 

Fig.  2.  Pig.  .•?. 


cz;> 


feeble  light.  Its  name,  from  the  Greek,  means 
water-maker.  A  candle  will  not  burn,  nor  can 
any  animal  live,  in  hydrogen  gas.  Mixed  with 
common  air,  it  explodes  with  great  violence  when 
brought  into  contact  with  flame.  It  is  the 
lightest  of  all  known  substances.  The  gas 
burned  in  the  streets  and  houses  is  hydrogen, 
mixed  with  a  peculiar  kind  of  carbon.  The  ex- 
plosions in  coal-mines  are  caused  by  a  mixture 
of  hydrogen  and  other  gases  with  the  air  we 
breathe,  which  are  set  on  fire  by  the  lamps  used 

Questions.  —  What  does  the  name  hydrogen  signify? 
What  its  effects  on  animal  life  ?  Will  it  burn  ?  Describe 
any  other  of  its  properties. 


AND    AGRICULTURE. 


17 


by  the  miner.     Hydrogen  is  one  of  the  constitu- 
ents of  water.     (See  Appendix,  3.) 

g.  4.  Fig.  5. 


OXYGEN  is  also  a  gas.  A  taper  burns  with 
increased  brilliancy  in  oxygen.  It  was  at  first 
called  vital  air.  It  is  heavier  than  hydrogen, 
and  heavier  than  the  atmosphere.  The  air  we 
breathe  contains  one-fifth  of  its  bulk  of  oxygen. 
Its  name  means  acid-maker.  It  combines  with  a 
^reat  many  substances,  forming  oxides :  the  rust 
on  iron  is  caused  by  oxidation,  and  most  earths 
are  only  metals  in  difierent  degrees  of  oxidation. 
Oxygen  is  one  of  the  constituents  of  water.     It 

Questions.  —  Of  what  is  hydrogen  one  of  the  constitu- 
ents ?  What  is  oxygen  ?  What  first  called  ?  Is  it  hea\ier 
than  the  atmosphere  ?  How  much  oxygen  does  the  atmos- 
phere contain  ?  What  are  oxides  ?  Of  what  fluid  is  oxygen 
one  of  the  constituents  ? 

2* 


18 


CHEMISTRY,    GEOLOGY 


Fig. 


is  the  best  supporter  of  combus- 
tion known.  Thin  iron  wire  will 
burn  readily  in  oxygen  gas,  throw- 
ing off  most  brilliant  sparks,  called 
scintillations. 

NITROGEN  is  also  a  gas.  A 
candle  will  not  burn,  nor  can  anv 
animal  live,  in  it.  It  is  sometimes 
called  azote^  which  means  against 
life.  It  does  not  burn  when 
brought  in  contact  with  flame.  It 
is  lighter  than  the  atmosphere. 
Although  it  destroys  animal  life, 
the  air  we  breathe  contains  four- 
fifths  of  its  bulk  of  nitrogen.  (  See 
Appendix,  5.) 

All  the  gases  hitherto  described 
are  colorless,  and  therefore  invis- 
ible. They  are  also  elastic,  which 
means  they  can,  by  great  press- 
ure, be  compressed  into  smaller 
bulk,  but  as  soon  as  the  pressure 


Questions.  —  W^hat  is  nitrogen  ?  Can  animals  live  in  it  ? 
What  was  its  old  name  ?  What  did  it  mean  ?  Will  nitrogen 
burn  ?  How  much  nitrogen  does  the  atmosphere  contain  ? 
Why  are  the  gases  described  invisible  ?  Are  they  elastic  ? 
What  is  the  effect  of  pressure  upon  them  ? 


AND   AGRICULTURE.  19 

is  removed,  tliej  resume  their  original  volume. 
The  Germans  first  called  these  elements  gases, 
which  meant  ghosts,  because  they  could  not  be 
seen ;  they  were  once  supposed  to  be  the  soul  or 
spirit  of  solid  matter. 

A  great  many  vegetable  substances  do  not 
contain  all  the  four  elementary  bodies  named 
and  described,  but  only  three  of  them,  namely, 
carbon,  hydrogen  and  oxygen;  all  the  bodies 
which  contain  no  nitrogen  are  called  non-azot- 
ized  substances. 

Starch,  sugar,  gum,  woody  fibre,  oils  and 
fats,  are  among  the  most  common  of  the  non- 
azotized  bodies,  or  those  which  contain  only  car- 
bon, hydrogen  and  oxygen.  Substances  which 
contain  nitrogen  are  called  azotized. 

Eight  or  ten  different  substances  are  found  in 
the  inorganic  part  of  plants :  these  are  potash, 
soda,  lime,  magnesia,    oxide   of  iron,  oxide  of 

Questions.  —  What  do  the  gases  do  if  the  pressure  is 
removed?  Are  all  the  four  preceding  elements  found  in 
vegetable  substances  ?  Which  is  not  found  in  a  great  many  ? 
Name  some  of  the  most  common  in  which  nitrogen  is  not 
found.  What  are  those  called  which  contain  no  nitrogen  ? 
What  those  which  contain  nitrogen?  How  many  sub- 
stances are  found  in  the  inorganic  part  of  plants  ?  Name 
them. 


20  CHEMISTRY,    GEOLOGY 

manganese,  silicia,  chlorine,  sulphuric  acid  and 
phosphoric  acid.     (See  Appendix,  6.) 

POTASH,  as  commonly  found,  is  called  a 
salt.  Its  base  is  a  metal  called  potassium.  The 
potash,  as  found  in  the  shops,  is  obtained  from 
wood-ashes,  by  boiling  them  in  water,  straining, 
and  then  boiling  down  to  dryness.  Potash  is 
thus  procured  by  leaching  wood-ashes,  to  which 
any  kind  of  fat  is  added,  the  mixture  is  boiled, 
and  it  becomes  soft-soap.  Potash  is  an  alkali ; 
it  absorbs  moisture  from  the  air,  and  soon  turns 
to  a  liquid.  Its  metallic  base,  potassium,  attracts 
oxygen  from  water  when  thrown  upon  it,  and 
takes  fire  as  it  floats  on  the  surface  of  the  water. 
(See  Appendix,  7.) 

SODA  is  also  an  alkali ;  it  is  made  from  sea 
salt.  Its  base  is  a  metal  called  sodium.  As  we 
buy  it  in  the  shops,  it  looks  like  pieces  of  coarse 
glass  ;  these  pieces  are  called  crystals.  If  ex- 
posed to  the  air,  it  soon  dries  and  crumbles  into 

Questions.  —  What  is  potash  ?  How  is  potash  obtained  ? 
What  is  its  base  called?  Boiled  with  fat,  what  does  it 
make  ?  What  is  potash  called  ?  How  does  the  air  act  upon 
it  ?  How  does  potassium  act  if  thrown  on  water  ?  What  is 
soda  ?  What  is  it  made  from  ?  What  is  its  base  called  ? 
What  do  its  crystals  look  like  ?    What  does  it  do  in  the  air  ? 


AND    AGRICULTURE.  21 

a  fine  white  powder.  Boiled  with  fats,  or  oil,  it 
makes  hard  soap.  (See  Appendix,  8.) 
•  LIME  is  a  well-known  substance.  It  looks 
like  pieces  of  white  earth.  It  is  an  alkali. 
Lime-stone  is  burned  in  a  kiln,  and  it  is  then 
called  quick-lime.  When  water  is  poured  on 
quick-lime,  it  slakes^  becoming  very  hot,  and 
throwing  off  a  great  deal  of  steam.  Slaked  lime 
is  in  the  form  of  a  white  powder.  It  is  used  in 
raakins  mortar,  which  is  a  mixture  of  slaked 
lime  and  sand.  It  has  also  a  metallic  base, 
which  is  called  calcium.  Chalk,  marble  and 
spar,  are  lime  combined  with  other  bodies,  called 
acids.  Bones  contain  much  lime,  and  so  do  oys- 
ter and  other  shells.  When  bones  and  shells  are 
burned  in  a  hot  fire,  their  organic  part  is  con- 
sumed, and  the  inorganic  part,  or  lime,  remains 
in  the  fire.  Egg-shells  are  almost  all  lime.  If 
fowls  cannot  get  lime,  or  something  which  con- 
tains lime,  their  eggs  are  soft,  and  have  no  shell. 
Lime  is  one  of  the  most  abundant  things  the 
earth  contains.     (See  Appendix,  9.) 

Questions.  —  Boiled  with  fkts,  or  oil,  what  does  soda 
make  ?  What  does  quick-lime  look  like  ?  How  is  it  made  ? 
What  effect  has  water  poured  on  lime  ?  Name  some  of  the 
varieties  of  lime.  What  is  lime  found  in  ?  Is  lime  very 
abundant  ? 


22  CHEMISTRY,  GEOLOGY 

MAGNESIA. — You  have  seen  the  magnesia 
sold  by  the  druggists,  or  in  the  shops.  It  is  in 
lumps,  very  white  and  powdery.  In  that  state 
it  is  called  carbonate  of  magnesia.  It  has  a 
metallic  base,  called  magnesium.  When  carbon- 
ate of  magnesia  is  burned  where  the  air  cannot 
get  at  it.  it  is  called  calcined  magnesia.  There 
is  a  kind  of  limestone  called  Magnesian^  from 
which  magnesia  is  procured.  It  is  also  obtained 
from  sea-w^ater.  Magnesia  is  a  very  mild  alkali. 
All  the  alkalies,  when  mixed  with  acids,  combine 
with  them,  and  make  w^hat  are  called  salts.  In 
the  act  of  uniting,  the  mixture  froths  up,  and 
looks  as  though  it  was  boiling.  This  boihng  up 
and  frothing  is  called  effej^vescence. 

IRON  is  a  well-known  metal.  It  is  the  most 
useful  of  all  the  metals.  It  is  found  in  the  earth, 
and  is  called  iron  ore.  Iron  is  obtained  by 
smelting  the  ore  in  large  and  very  hot  furnaces. 
Steel  is  iron  combined  with  carbon.  Iron  is  a 
soft  metal,  steel  is  very  hard.     Iron  is  ductile, 

Questions.  —  What  do  you  know  about  magnesia  ?  What 
is  calcined  magnesia  ?  What  is  it  obtained  from  ?  What  is 
its  metallic  base  called  ?  What  do  the  alkalies  do  when  mixed 
with  acids }  What  is  the  frothing  up  called  ?  Can  you  tell 
me  anything  about  iron  ?  Where  is  iron  found  ?  How  is  it 
obtained  ? 


AND   AGRICULTURE. 


23 


which  means  that  it  can  be  drawn  out  very  fine ; 
and  it  is  malleable, —  that  is,  it  can  be  rolled  or 
hammered  out  very  thin.     (See  Appendix,  10.) 

OXIDE  OF  IRON.  —  If  iron  is  exposed  to 
the  atmosphere,  it  becomes,  after  a  while,  cov- 
ered with  a  reddish-brown  powder,  or  rust ;  this 
rust  is  oxide  of  iron ;  the  iron  has  attracted  a 
portion  of  oxygen  from  the  atmosphere,  and 
combined  with  it.  Metals  will  not  oxidize  in  a 
dry  place,  or  protected  from  moisture.  (See 
Appendix,  11.) 

Sometimes  the  oxide  of  manganese,  a  sub- 
stance very  much  like  the  oxide  of  iron,  is  found 


Fig.  8. 


Questions,  —  What  is  the  rust  of  iron  ?  Will  metals  ox- 
idize in  a  dry  air  ?  What  oxide,  much  like  iron,  is  some- 
times found  in  soils  and  plants  ? 


24 


in  soils  and  plants  ;  but  it  is  usually,  when  found 
at  all,  only  in  very  small  quantities. 

SILICIA  is  the  name  by  which  the  chemist 
designates  the  several  varieties  of  flint,  rock- 
crystal,  sand-stone,  etc. 

CHLORINE  is  a  gas  having  a  strong,  suffo- 
cating smell,  and  a  greenish-yellow  color.  It  is 
twice  and  a  half  heavier  than  the  atmosphere. 
A  taper  burns  in  it  with  a  dull,  smoky  flame.  It 
takes  the  color  out  of  almost  all  vegetable  sub- 
stances ;  hence  it  is  sometimes  called  the  bleaching 
gas.  One  hundred  pounds  of  common  salt  contain 
sixty  pounds  of  chlorine.     [See  Appendix,  12. J 

SULPHURIC  ACID  is  often  called  oil  of 
vitriol,  but  the  first  is  its  proper  name.  It  is 
made  by  burning  brimstone  and  saltpetre  in 
leaden  chambers,  containing  water  on  their  floors. 
It  is  exceedingly  sour,  and  decomposes  vegetable 
or  animal  substances  when  poured  upon  them. 
Sulphuric  acid  is  found  in  gypsum,  alum,  Epsom 
salts,  and  many  other  substances.       Combined 

Questions,  —  What  is  silicia  ?  What  is  chlorine?  Is  it 
heavier  than  the  atmosphere  ?  How  much  heavier  ?  How 
does  a  taper  burn  in  it  ?  Why  is  it  called  the  bleaching  gas } 
How  much  chlorine  is  there  in  one  hundred  pounds  of  com- 
mon salt  ?  What  is  sulphuric  acid  often  called  ?  How  is  it 
made  ?  What  effect  has  it  on  organic  substances  ?  In  what 
is  it  found  ? 


AND    AGRICULTURE.  25 

with  alkalies,  it  forms  salts.  It  is  so  acrid  that 
it  burns  or  destroys  wherever  it  drops  upon 
organic  substances.  It  is  composed  of  sulphur 
and  oxygen.  Combining  with  water,  it  gives 
out  a  very  intense  heat,  often  breaking  the  ves- 
sel in  which  the  mixture  is  incautiously  made. 
[See  Appendix,  13.] 
PHOSPHORIC  ACID  is  oxygen  combined 
Fig.  9.  with  phosphorus.      Phos- 

phorus is  so  very  inflamma- 
ble that  it  can  only  be 
handled  with  the  greatest 
care.  It  is  slowly  con- 
sumed in  the  air,  emitting 
white  fumes  ;  these  fumes 
are  phosphoric  acid.  You  may  learn  its  smell 
from  a  lucifer-match,  if  you  just  rub  it,  without 
setting  it  on  fire.  Phosphorus  exists,  in  large 
quantities,  in  the  bones  of  animals,  and  it  is  pre- 
pared in  very  great  quantities  for  the  use  of 
match-makers.     [See  Appendix,  14.] 

All  these  substances,  in  different  proportions, 

Questions,  —  What  does  it  make  with  alkalies  ?  Of  what 
is  it  composed  ?  What  is  phosphoric  acid  ?  Is  phosphorus 
very  inflammable  ?  How  should  it  be  handled  ?  How  miiy 
you  learn  its  smell  ?    In  what  is  it  abundantly  found  ? 

3 


26 


are-  found  in  the  inorganic  part,  or  ashes,  of  our 
commonly  cultivated  plants.  But  some  plants 
yield  a  much  larger  quantity  of  ashes  than 
others.  One  hundred  pounds  of  dry  hay  will 
yield,  after  burning,  from  eight  to  ten  pounds  of 
ashes ;  but  the  same  weight  of  wheat  will  only 
give  between  one  and  two  pounds  of  ashes. 

The  proportions  in  which  these  substances  are 
found  in  the  ashes  of  different  plants  differs  very 
mucL  The  ashes  of  hay  contain  much  more 
lime  than  the  ashes  of  wheat, —  and  the  wheat- 
.ash  contains  more  phosphoric  acid  than  the  hay. 

These  facts  are  of  the  greatest  practical  im- 
portance to  the  farmer,  as  we  shall  soon  be  able 
to  show  our  young  friends;  and  many  lands 
have  been  ruined  because  the  farmer  neither 
knew  the  nature  of  his  soil  nor  the  food  his  crops 
'  consumed.  ' 

THE   FOOD    OF   PLANTS. 

Plants  require  constant  supplies  of  food,  to 
enable  them  to  live  and  grow ;  without  suitable 
and  abundant  food,  they  soon  die. 

Questions.  —  Are  all  the  substances  described  found  in 
the  asbes  of  plants  ?  Do  all  plants  leave  the  same  weight  of 
ashes  when  burned  ?  Do  the  ashes  of  different  plants  dijQfer 
lin  the  proportion  of  these  constituents  ?  Do  plants  need  fix)d  ? 


AND    AGRICULTURE. 


27 


Plants  obtain  their  food  in  part  from  the  air, 
and  in  part  from  the  soil :  their  leaves  drink  it 
in  from  the  air,  and  their  roots  take  it  up  from 
the  soil.  Nor  can  they  thrive  alone  upon  one 
kind  of  food :  they  must  have  two  distinct  kinds 
of  food ;  they  must  have  organic  food  to  support 
their  organic  part,  and  inorganic  food  to 
strengthen  their  inorganic  part.  Their  organic 
food  is  derived  from  the  air  and  the  soil ;  their 
inorganic  food  is  obtained  from  the  soil  alone. 

Fig.  11. 


Fig.  10. 


Questions.  — Where  do  plants  obtain  food  ?  How  do  they 
obtain  it  ?  How  many  kinds  of  food  do  they  need  ?  Where 
do  they  get  their  organic  food  ?     Where  their  inorganic  food  ? 


28  CHEMISTRY,    GEOLOGY 

Carbonic  acid  gas  is  the  form  of  food  they  main- 
ly derive  from  the  air.  This  gas  has  no  color, 
but  it  has  a  peculiar  smell.  It  is  so  heavy  that 
it  can  be  poured  from  vessel  to  vessel,  like  water. 
It  extinguishes  burning  bodies,  and  destroys 
animal  life  when  breathed.  It  causes  the  spark- 
ling of  soda-water  and  the  frothing  of  beer,  and 
forms  nearly  half  the  weight  of  all  limestone 
rocks.  Animals  throw  carbonic  acid  gas  out 
in  breathing,  and  plants  drink  it  in.  (See  Ap» 
pendix,  15.) 

The  quantity  of  carbonic  acid  gas  in  the  at- 
mosphere is  very  small,  only  about  two  gallons 
in  five  thousand ;  the  air  we  breathe  is  almost 
wholly  oxygen  and  nitrogen :  in  five  gallons  of 
the  atmospheric  air,  there  are  four  gallons  of 
nitrogen  and  one  of  oxygen.  Although  the 
atmosphere  contains  only  the  comparatively  small 
quantity  of  carbonic  acid  named,  yet  plants 
drink  it  in  freely,  from  the  abundance  of  their 
leaves,  which  contain  a  great  number  of  small 

Questions.  —  In  what  form  do  plants  take  food  from  the 
air  ?  "What  is  carbonic  acid  gas  ?  Describe  some  of  its 
properties.  Is  there  much  carbonic  acid  in  the  atmosphere  ? 
In  what  proportion  is  it  found  ?  How  do  plants  obtain  the 
caibonic  acid  from  the  air  ? 


AND   AGRICULTURE. 


29 


Fig.  12. 


openings,  or  mouths,  spread  all  over  their  surface, 
but  especially  on  their  under  side.  Plants  take 
in  carbonic  acid  only  during  the  day ;  during  the 
night  they  give  it  off. 

Twenty-two  pounds  of  carbonic  acid  gas  con- 
tain six  pounds  of  carbon  and  sixteen  of  oxygen ; 
and  this  is  readily  proved  by  burning  charcoal  in 
oxygen.     (See  Appendix,  16.) 

Plants   only  retain 
the   carbon  contained 
in  the  carbonic  acid; 
they  give  the  oxygen 
back  again  to  the  air. 
We  can  prove  this  very 
easily.      Fill  a  tum- 
bler with  clear  water ; 
put  into  it  a  few  fresh 
green  leaves ;  then  in- 
vert the  tumbler  in  a  saucer,  so  that  it  shall 
remain  full.     Place  it  in  the  sun,  and  bubbles 
;  of  oxygen  may  be  seen  arising  from  the  leaves, 
occupying  the  upper  part  of  the  tumbler. 

Questions.  —  Do  the  leaves  take  in  carbonic  acid  all  the 
I  time  ?    Of  what  is  carbonic  acid  composed  ?     Can  you  prove 
this }    Do  plants  retain  all  the  carbonic  acid  ?     How  can 
you  prove  they  give  back  the  oxygen  ? 

3* 


30  CHEMISTRY,    GEOLOGY 

N 

Besides  carbonic  acid  gas,  the  leaves  of  plants 
drink  in  watery  vapor  from  the  atmosphere, 
which  moistens  the  leaves  and  stems,  and  at  the 
same  time  adds  to  the  substance  of  the  plant. 

Plants  take  up  carbon  from  the  soil  in  the 
form  of  carbonic  acid,  humic  acid,  and  some  other 
combinations  in  which  it  exists  in  the  vegetable 
matters  of  the  soil  (see  Appendix,  17)  ;  and 
they  obtain  nitrogen  from  the  soil  in  the  forms 
of  ammonia  and  nitric  acid,  which  we  shall  be- 
fore long  describe  to  our  young  friends. 

SUBSTANCES  IN  THE  STRUCTURE  OF  PLANTS. 

Plants  are  mainly  made  up  of  woody  fibre, 
starch,  and  gluten.  The  woody  fibre  constitutes 
the  greater  part  of  every  kind  of  wood,  straw, 
hay,  chaff,  cotton,  flax,  hemp,  the  shells  of  nuts, 
etc. 

Starch  is  first  seen  in  the  form  of  a  white 
powder.  Nearly  the  whole  substance  of  the 
potato  is  starch,  and  nearly  half  the  weight  of 

Questions.  —  Do  plants  drink  anything  from  the  atmos- 
phere bes'Mes  carbonic  acid  ?  W^hat  use  do  they  make  of 
writer  ?  IIow  do  they  take  up  carbon  from  the  soil  ?  Whence 
do  they  obtain  nitrogen  ?  What  substances  enter  into  the 
structure  of  plants  ?  What  does  the  woody  fibre  form  ? 
What  is  starch  ? 


AND   AGRICULTURE. 


81 


I 


oat-meal,  the  flour  of  wheat,  and  of  all  other 
grains  cultivated  for  food. 

Fig.  13.  Gluten  is  a  sticky, 

tenacious       substance, 
found  along  with  the 
starch,    in    almost   all 
plants.       It    may    be 
easily    obtained    from 
wheat-flour,   by    mak- 
ing  it   into  a   dough, 
and    then     repeatedly 
washing  it  with  water. 
(See  Appendix,  18.) 
In  the  stems  of  plants  the  woody  fibre  is  the 
most  abundant,  and  starch  is  most  abundant  in 
their  seeds :  starch  is  also  very  abundant  in  the 
potato,  and  other  roots  of  a  similar  kind. 

Woody  fibre,  starch,  gum  and  sugar,  all  con- 
sist of  carbon  and  water  only ;  and,  as  water 
contains  hydrogen  and  oxygen,  the  articles  just 
named  consist  of  carbon,  hydrogen  and  oxygen. 


Questions.  — ^What  is  gluten  ?  How  may  gluten  be  ob- 
tained ?  Which  of  the  substances  named  is  most  abundant 
in  the  stems  of  plants  ?  Which  in  the  seeds  ?  Does  starch 
exist  in  the  roots  of  plants  ?  Of  what  do  woody  fibre* 
starch,  gum  and  sugar,  consist  ? 


I. 


32  CHEMISTRY,    GEOLOGY 

Now,  if  you  remember  that  plants  drink  in  carbon- 
ic acid  and  water,  you  will  see  that  they  can  form 
all  these  very  unlike  substances  therefrom ;  and, 
as  the  leaves  require  only  carbon  and  water  to 
form  the  woody  fibre  and  starch  of  which  they 
are  composed,  they  give  off  the  oxygen  of  the 
carbonic  acid  because  they  cannot  make  any  use 
of  it.     (See  Appendix,  19.) 

Notwithstanding  plants  drink  in  so  much  car- 
bonic acid  from  the  air,  they  can  never  exhaust 
it,  because  new  supplies  are  being  continually 
thrown  into  it  from  other  sources,  which  are 
three  in  number :  — 

1.  From  the  breathing  of  animals;  for  all 
animals  throw  a  small  portion  of  carbonic  acid 
into  the  air,  every  time  they  breathe. 

2.  From  the  combustion  of  wood,  coal,  can- 
dles, oil,  etc.;  for  all  these  things  contain  carbon, 
which,  as  they  burn  in  the  air,  form  carbonic 
acid,  as  the  charcoal  did  when  burned  in  oxygen. 

3.  From  the  decay  of  vegetables  and  roots ; 
for  decay  is  only  a  slow  kind  of  combustion, 

Questions.  —  Can  all  these  be  formed  from  the  food  the 
leaves  drink  in  ?  Why  do  the  leaves  give  out  the  oxygen  of 
the  carbonic  acid  ?  Why  do  not  plants  exhaust  the  air 
of  aU  its  carbonic  acid }  From  whence  does  the  air  obtain 
carbonic  acid  ? 


AND   AaRICULTURE.  88 

whereby  the  carbon  of  plants  is  changed  into  car- 
bonic acid. 

Thus  it  is  seen  how  wisely  Infinite  Wisdom 
has  adapted  every  fact  in  nature  to  some  purpose 
of  good.  Animals  produce  and  throw  off  car- 
bonic acid  and  Avater,  and  plants  take  in  and  live 
upon  the  carbon  thus  thrown  off.  Having  drank 
in  the  carbonic  acid  by  its  numberless  mouths, 
the  plant  transforms  it  and  water  into  starch, 
sugar,  etc.,  upon  which  animals  live. 

The  fibre  of  wood,  starch,  sugar  and  gum, 
contain  carbon  and  water  only ;  water  is  only 
oxygen  and  hydrogen.  Nine  pounds  of  water 
contain  about  eight  pounds  of  oxygen  and  one 
pound  of  hydrogen.  Water,  as  you  know,  ex- 
tinguishes fire ;  and  yet  it  is  composed  of  two 
gases,  one  of  w^hich,  the  hydrogen,  burns  very 
readily,  and  in  the  other,  the  oxygen,  bodies 
bum  wuth  increased  brilliancy.  This  fact  ap- 
})ears  v/onderful,  but  there  are  many  other  sub- 
stances whose  composition  is  equally  astonishing. 
White  starch  consists  of   black  charcoal  and 


Questions. —  By  whom  is  carbonic  gas  thrown  out? 
\V  hat  do  plants  do  with  the  carbon  thrown  off  by  animals  ? 
What  does  water  consist  of?  In  about  what  proportions? 
Of  what  does  starch  consist  ? 


34 


CnEMISTRY,    GEOLOGY 


Fig.  14. 


water  only,  and  sugar  and  gum  contain  exactly 
the  same  elements  as  starch  and  the  fibre  of 
wood.  Now,  as  water  contains  hydrogen  and 
oxygen,  the  substances  which  consist  of  carbon 
and  water  really  contain  carbon,  hydrogen  and 
oxygen.     (See  Appendix,  20.) 

That  water  really  contains  on- 
ly hydrogen  and  oxygen  gases, 
may  be  very  easily  proved  by 
burning  hydrogen  in  oxygen. 
Put  into  the  bottle  (Fig.  14) 
a  few  old  nails,  or  clippings  of 
zinc,  and  pour  upon  them  sul- 
phuric acid  diluted  with  four  or 
five  times  its  measure  of  water. 
Hydrogen  gas  will  thus  be  formed 
^^  rapidly.  Having  put  the  stem 
of  a  tobacco-pipe  through  a  cork, 
the  size  of  the  neck  of  the  bottle, 
close  it  therewith.  The  gas  will  soon  rise  through 
the  pipe.  When  the  gas  has  escaped  a  few 
minutes,  the  jet  may  be  lighted  from  a  match. 

Questions. —  Can  you  tell  me  any  other  substances  which, 
contain  only  carbon  and  water  ?  What  do  those  substances 
which  contain  only  carbon  and  water  really  consist  of? 
How  can  you  show  that  water  contains  only  hydrogen  and 
oxygen  ? 


AND   AGRICULTURE.  35 

Then  take  a  dry  glass  tube,  from  ten  to  twenty 
inches  long,  and  about  one  inch  in  diameter,  and 
pass  it  over  the  jet,  as  in  the  cut.  A  musical 
sound  will  be  heard  issuing  from  the  tube,  which 
will  soon  become  moist  on  the  inside.  If  a  tube 
is  not  to  be  had,  a  dry  tumbler  may  be  used, 
and  the  water  produced  will  be  condensed  inside 
it.  Now,  whence  came  the  water  7  The  hydro- 
gen gas,  in  burning,  united  with  just  suflBcient 
of  the  oxygen  contained  in  the  air  to  make  water. 
Gluten,  unhke  the  substances  already  de- 
scribed, contains  four  elements  ;  it  contains  nitro- 
gen, in  addition  to  carbon,  hydrogen  and  oxygen. 
The  nitrogen  which  plants  require,  to  make  glu- 
ten, is  obtained  almost  wholly  from  the  soil. 

OF  THE  SUBSTANCES  WHICH  FORM  SOIL. 

The  soil  contains  two  kinds  of  matter, — organic, 
or  the  part  which  is  combustible ;  and  inorganic, 
or  the  part  which  will  not  burn. 

This  may  be  shown  by  heating  a  small  portion 

Questions, —  Where  does  the  hydrogen,  in  burning,  get  the 
oxygen  necessary  to  make  water  ?  How  many  elements  does 
gluten  cpntain  ?  Name  them.  Whence  do  plants  obtain 
their  nitrogen  ?  How  many  kinds  of  matter  are  there  in 
Boil  ?     Name  them. 


86  CHEMISTRY,    GEOLOGY 

Fig.  15.  of  soil  to  redness, 

on  a  strip  of  sheet 
iron  (see  Fig. 
15),  over  a  lamp. 
The  soil  first 
^blackens,  proving 
the  presence  of 
^  carbon ;  and,  as 
the  carbonaceous  matter  burns  awdj,  the  soil 
becomes  a  gray -brown,  or  reddish  color.  (See 
Appendix,  21.) 

The  organic  part  is  obtained  from  roots  and 
stems  of  decayed  vegetable  and  animal  matter, 
and  from  dung  and  other  manures.  In  peaty 
soils,  the  organic  part  forms,  often,  three-quar- 
ters of  their  whole  weight ;  but  in  rich  and  fertile 
land  it  is  not  often  more  than  from  one-twentieth 
to  one-tenth  of  their  weight. 

In  our  country,  soils  which  do  not  contain  a 
full  proportion  of  organic  matter  cannot  yield 
good  crops.      A  rich  soil  should  consist  of  at 

Questions.  —  How  can  we  prove  that  soil  contains  two 
kinds  of  matter  ?  Which  burns  away  ?  W' hich  part  is  not 
consumed  ?  Whence  does  soil  obtain  its  organic  matter  ? 
What  is  its  quantity  in  peat  lands  ?    What  in  good  soil  ? 


AND    AGRICULTURE.  37 

least  one- twentieth,  or  five  per  cent.,  of  organic 
matter. 

If  land  is  ploughed  and  planted  year  after  year, 
and  but  little  manured,  the  organic  matter  is  ex- 
hausted, and  the  crops  are  poor ;  but  when  the 
soil  is  put  to  permanent  pasture,  or  sufficiently 
enriched  with  farm-yard  or  other  appropriate 
manure,  as  peat,  compost,  or  guano,  it  is  not  im- 
poverished, because  the  crops  do  not  exhaust  it 
of  its  organic  matter. 

The  quantity  of  organic  matter  plants  take  up 
from  the  soil  differs  greatly,  depending  on  the 
kind  of  land,  the  nature  of  the  plant,  and  the 
season ;  but  they  always  take  up  a  good  deal,  and 
it  is  essential  for  the  health  and  perfection  of  the 
plant. 

The  requisite  supply  of  organic  matter  in  the 
soil  may  be  insured  by  ploughing  in  green  crops, 
by  sowing  clover,  and  the  grasses,  which  leave 
abundant  roots  in  the  soil,  and  by  restoring  the 

Questions How  much  organic  matter  should  land  con- 
tain, to  produce  good  crops?  What  impoverishes  land? 
How  can  it  be  kept  from  being  exhausted  by  crops  ?  Do  all 
plants  take  the  same  quantity  of  organic  matter  from  the 
soil  ?  Why  do  they  thus  differ  ?  Why  is  organic  matter 
essential  for  the  plant  ?  How  may  the  requisite  supply^  of 
organic  matter  be  retained  in  the  land  ? 

4 


38  CHEMISTRY,    GEOLOGY 

woodj  fibre  of  vegetables,  as  hay,  straw,  corn- 
stalks, etc.,  in  the  form  of  manure. 

The  inorganic  or  incombustible  part  of  the 
soil  is  derived  from  the  gradual  crumbling  down 
of  different  kinds  of  rocks.  The  decaying  walls 
of  buildings,  the  substance  called  rotten  rock^  — 
which  is  trap  or  whinstone  in  a  decomposed  state. 
—  limestone,  gravel,  etc.,  are  also  sources  which 
supply  inorganic  matter  to  the  soil. 

Rocks  consist,  to  a  large  extent,  of  sandstones, 
limestones,  and  clays.  Of  the  sandstones,  there 
are  the  red,  and  the  white,  and  other  freestones. 
Limestones  include  chalk,  gypsum,  the  blue, 
and  other  varieties.  Clays  comprise  the  skte 
used  for  roofing,  and  the  shale  or  shiver  of  the 
coal  beds.  All  the  inorganic  part  of  soils  main- 
ly consists  of  sand,  clay,  and  lime. 

Sometimes  soil  contains  one  of  these  substances 
in  a  much  larger  quantity  than  either  of  the 
others.  When  sand  is  most  abundant,  the  land 
is  called  i^andy  soil.  If  the  clay  greatly  pre- 
dom'nates,  it  is  a  stiff,  or  clay  soil.     If  the  lime 

Questions,  —  Whence  does  the  soil  derive  its  inorganic 
part  ?  Of  what  do  rocks  chiefly  consist  ?  Name  some  of 
the  varieties  of  sandstones.  Of  limestones.  Of  clays. 
When  soil  contains  most  sand,  what  is  it  called  ?  What, 
when  clay  is  most  abundart  ? 


AND   AGRICULTURE.  39 

is  in  the  greatest  quantity,  it  is  a  calcareous  soil. 
The  word  calcareous  is  made  from  the  Latin  word 
calx^  which  means  lime ;  therefore,  a  calcareous 
soil  is  one  that  contains  a  great  deal  of  lime. 

Sand  and  clay,  with  only  a  moderate  quantity 
of  lime,  is  called  a  loam ;  if  the  lime  is  more 
abundant,  it  is  then  a  calcareous  loam;  if  the 
clay  is  in  large  quantity,  with  an  abundance  of 
lime,  it  is  a  calcareous  clay. 

When  lands  contain  a  large  quantity  of  sand 
or  gravel,  they  are  called  light  lands ;  when  the 
soil  contains  a  large  proportion  of  clay,  it  is  then 
known  as  heavy  land. 

The  light  lands  are  most  easily  cultivated,  and 
they  are  often  called  barley  or  turnip  soils,  be- 
cause they  are  best  fitted  for  barley,  turnips,  or 
green  crops. 

Both  light  and  heavy  lands  require  draining. 
Clay  land  retains  the  most  water,  and  it  often  is 
seen  on  the  surface  of  the  soil.     But  sandy  soils, 

Questions,  —  What  is  soil  called  when  lime  is  in  greatest 
quantity  ?  What  is  the  meaning  of  calcareous  ?  What  is 
loam  ?  What  is  a  calcareous  loam  ?  What  is  a  calcareous 
clay  ?  What  are  light  lands  ?  What  are  heavy  lands  ?  W  hat 
crops  are  best  fitted  for  light  soils  ?  What  lands  require 
draining  '  What  difference  is  there  in  light  and  heavy  lands 
a*  regards  water  f 


40  CHEMISTRY,    GEOLOGY 

although  generally  dry  on  the  surface,  are  often 
so  wet  below  as  to  require  drains  to  carry  off  the 
excess  of  water. 

A  drain  should  seldom  be  less  than  thirty 
inches  deep ;  because  the  deeper  the  soil  is  made 
dry,  the  deeper  the  roots  of  plants  will  descend 
in  search  of  food.  If  the  drains  are  as  deep  as 
thirty  inches,  the  soil  can  be  turned  up  with  the 
subsoil  plough  to  the  depth  of  nearly  two  feet, 
without  running  the  risk  of  injuring  them. 

Draining  is  beneficial  to  the  land  for  other 
reasons.  Drains  admit  air  to  the  subsoil,  and 
they  allow  the  rain  to  sink  down  and  wash  out 
of  it  many  substances  which  would  be  injurious 
to  the  crops.  It  is  not  uncommon  for  crops, 
which  at  first  look  very  promising,  to  droop  and 
fail  when  their  roots  reach  the  injurious  sub- 
stances in  the  subsoil. 

Heavy  or  clay  lands  are  often  let  stand  as 
permanent  pasture,  because  the  labor  and  expense 
of  ploughing  and  working  them  is  so  great,  that 
the  crops  of  grain  obtained  from  them  do  not  re- 

Questions.  —  How  deep  should  drains  be  ?  Why  ?  Do 
you  know  any  other  reason  for  deep  drains  ?  Of  what 
other  advantage  is  draining  ?  Are  ci-ops  ever  injured  by  the 
substances  contained  in  the  subsoil  of  undrained  lands  > 
Why  are  clay  lands  often  let  stand  in  pasture  ? 


AND    AGRICULTURE.  41 

turn  to  the  farmer  a  sufficient  compensation. 
But  these  lands  could  be  made  lighter,  more 
easily  cultivated,  and  yield  very  productive  crops, 
if  they  were  drained,  subsoil  ploughed,  and  lime 
or  marl  added  as  required.  When  thus  improved, 
their  yield  of  grain  will  be  increased  by,  some- 
times, scores  of  bushels  to  the  acre;  and  the 
cost  of  draining  and  improving  is  usually  paid 
back  to  the  farmer  in  three  or  four  years,  from 
the  largely  increased  yield  and  more  profitable 
nature  of  the  crops. 

THE   INORGANIC   FOOD    OF   PLANTS. 

The  inorganic,  or  earthy  part  of  soil,  answers 
a  double  purpose  :  first ^  it  keeps  the  plants  in  a 
firm  and  upright  position,  because  their  roots  are 
securely  held  therein  :  and  second,  it  furnishes 
the  plant  with  that  food  which  it  requiies  for  the 
perfection  and  growth  of  its  inorganic  parts. 

In  addition  to  the  sand,  clay  and  lime,  of 
which  the  inorganic  part  of  soils  mainly  consists, 
they  also  contain  small  amounts  of  potash,  soda, 

Questions, — How  could  clay  land  be  made  more  profitable  ? 
Do  draining  and  other  improvements  pay  the  farmer  for 
their  cost  ?  Of  what  use  is  the  inorganic  part  of  the  soil  ? 
What  substances  does  the  soil  contain  besides  sand,  clay,  and 
lime  ? 

4* 


42  CHEMISTRY,     GEOLOGY 

magnesia  oxide  of  iron,  oxide  of  manganese, 
sulphuric  acid,  phosphoric  acid,  and  chlorine. 
These  substances  are  found,  in  different  propor- 
tions, in  the  ashes  or  inorganic  part  of  all  plants, 
and  the  plants  derive  them  solely  from  the  soil, 
as  none  of  them  are  found  in  the  air. 

Plants  take  up  these  inorganic  substances 
through  their  roots ;  but  before  they  can  do  so 
they  must  be  dissolved,  or  made  into  a  solution, 
by  the  rain  water,  or  the  waters  of  springs.  So 
long  as  they  remain  solid,  or  undissolved,  they 
are  valueless  to  the  plant,  Avhich  can  derive  no 
food  from  them.     (See  Appendix,  22.) 

All  fertile  or  productive  soils  must  contain 
these  inorganic  substances ;  because  without  them 
plants  must  languish,  and  the  crops  be  poor  and 
unproductive. 

All  plants  do  not  require  the  same  quantity 
of  all  these  substances  ;  some  take  up  a  large 
quantity  of  one  or  more  of  them,  and  only  a  very 
small  portion  of  the  others.  (See  Appendix,  23.) 

Questions.  —  AVhere  are  the  last-named  substances  found, 

besides  in  the  soil  ?    Do  plants  take  them  up  ?    How  do  they 

take  thera  up  ?     In  what  form  do  they  take  them  up  ?    Must 

fertile  soils  possess  these  inorganic  substances  ?     Why  ?     Do 

'  all  plants  require  the  same  proportion  of  these  substances  ? 


AND    AGRICULTURE. 


43 


The  following  table  shows  the  quantity  of 
ashes  left  after  burning  one  thousand  pounds  of 
hay,  made  from  the  different  grasses  named,  and 
the  composition  of  the  ashes  of  the  several  kinds 
of  grass.     (See  Appendix,  23.) 


Inorganic  Substances. 


Potash,      .    .    .    . 

Soda, .   

Lime, 

Magnesia,.  .  .  . 
Oxide  of  Iron, .    . 

Silicia, 

Sulphuric  Acid,  . 
Phosphoric  Acid, . 
Chlorine,  .    .   .   . 


Rye 
Gx-ass. 


.  9 
.  4 
.  7 
.  1 
trace 
.28 


trace 
53 


Red 
Clover. 


.20 
.    5i 
.28 
.    3 
trace 
.    4 
.    4^ 
.    6^ 


74| 


Wliite 
Clover. 

.31 
.    6 

.    3 

.15 


80^ 


Lucerne 


13i 

6 

48 

3^ 


.  4 
.13 
.    3 


94| 


Now,  you  will  see  that  unless  the  soil  contains 
all  the  substances  found  in  the  ashes  of  plants, 
the  plants  cannot  grow  perfectly  ;  and,  although 
some  of  those  substances  are  only  found  in  very 
small  quantities  in  the  plant,  yet  their  presence 
is  necessary  for  its  health  and  life. 


Questions.  —  What  does  the  ta-ble  show  ?  How  many 
pounds  of  ashes  in  one  thousand  pounds  of  rye  grass  ?  In 
red  clover  ?  In  white  clover  ?  In  lucerne  ?  Are  sub- 
stiinces,  found  only  in  very  small  quantity  in  the  plant, 
necessary  in  the  soil  ? 


44  CHEMISTRY,    GEOLOGY 

If  a  soil  was  wholly  destitute  of  one  of  these 
substances,  it  could  not  yield  good  crops ;  and  if 
it  contained  an  abundance  of  them  all,  with  but 
a  single  exception,  and  that  found  only  in  a  very 
small  amount,  plants  which  required  only  a  very 
small  quantity  of  that  substance  would  thrive 
well  on  such  soil ;  but  those  which  required  a 
large  quantity  of  that  substance  of  which  the  soil 
contained  only  very  little,  would  be  stunted,  un- 
healthy, and  unproductive. 

Suppose  a  piece  of  land  contained  only  a  small 
quantity  of  lime,  you  will  find,  on  looking  at  the 
table  of  ashes,  that  rye  grass,  which  contains 
very  little  lime,  would  do  well  on  that  soil ;  but 
lucerne,  which  contains  a  great  deal  of  lime, 
would  not  be  likely  to  thrive  on  land  which  con- 
tains only  a  small  quantity  of  that  substance. 
Rye  grass  would  grow  well  on  soil  containing  an 
abundance  of  sand,  but  lucerne  would  not  so  well. 
Rye  grass  requires  very  little  phosphoric  acid  in 
the  soil ;  lucerne  rec^uires  a  much  larger  quan- 
tity. 

Questions.  —  What  would  be  the  result  of  a  soil  contain- 
ing none  of  some  one  of  these  substances  ?  What  would  be 
the  result  of  soil  containing  plenty  of  all  these  substances, 
with  only  a  small  quantity  of  some  one  of  them  ?  Give  an 
illustration  of  the  fact  just  named. 


AND   AGRICULTURE. 


45 


If  in  any  soil  most  of  these  inorganic  sub- 
stances were  absent,  it  would  be  naturally  bar- 
ren, and  no  good  or  productive  crops  of  any  kind 
could  be  raised  from  it.  There  are  many  large 
tracts  of  land,  in  all  countries,  which  have  never 
been  under  cultivation,  that  are  naturally  fertile 
and  productive,  and  many  other  tracts  which  are 
naturally  barren  and  unproductive. 

In  naturally  fertile  soils  all  those  inorganic 
substances  are  found  which  are  required  by  our 
cultivated  crops  for  food ;  in  barren  soils  some 
of  these  substances  are  wholly  wanting. 


Ornranic  matter, 

Silicia  (in  the  sand  and  clay), 

Alumina  (in  the  clay), 

Lime 

Magnesia, 

Oxide  of  iron, 

Oxide  of  manganese, 

Potash,     .   

a;lo;ine,|^^^^«y^«<^°°^-«^i^' — ■•  •  • 

Sulphuric  acid, 

Phosphoric  acid, 

Carbonic  acid,  comb,  with  lime  and  magnesia, 

Loss, 

Parts, 


i\iU\r 

F..ini. 

■  ithonl 

will) 

Barren 

iLiniir. 

fiiKnurt' 

97 

50 

40 

648 

833 

778 

57 

51 

91 

69 

18 

4 

8.^ 

8 

1 

61 

30 

81 

1 

3 

4 

2 

trace 

trace 

n 

2 

i 

4', 

i;i 

40 

4' 

14 
1000 

4V 

lOUO 

1000 

The   above  table  shows   the   composition   of 

Questions.  —  What  makes  soil  barren  ?     What  is  the  dif- 
ference between  naturally  fertile  and  naturally  barren  soils  ? 


\6  CHEMISTRY,    GEOLOGY 

soils  naturally  fertile,  artificially  fertilized,  and 
barren:  — 

The  soil  whose  composition  is  found  in  the 
first  column  of  the  table  had  yielded  good  crops 
for  sixty  years  without  manure,  and  yet  con- 
tained an  appreciable  amount  of  all  the  inorganic 
substances  required  by  plants.  The  soil  de- 
scribed in  the  second  column  produced  good 
annual  crops  by  the  addition  of  appropriate 
manures ;  it  was  deficient  of  three  or  four  sub- 
stances, which  were  supplied  by  the  manures. 
The  third  was  irrecoverably  barren ;  it  was 
deficient  of  substances  wh^.h  none  of  the  ordi- 
nary manures  could  supply. 

Notwithstanding  a  soil  contaihv.  the  inor- 
ganic substances  required  by  plants  as  food,  it 
may  be  still  unproductive  or  barren,  by  the  pres- 
ence of  some  one  largely  in  excess.  The  oxide 
of  iron,  when  present  in  a  very  large  amount  in 
soil  otherwise  good,  would  render  it  incapable  of 
producing  good  crops. 

To  remedy  this  evil,  the  land  should  be  thor- 
ough drained  and  subsoiled,  so  that  the  rains 
might  easily  penetrate  it  and  wash  out  the  inju- 

Questions.  — ^What  will  cause  a  soil,  in  other  respects  good, 
to  be  unproductive  ?     How  may  that  defect  be  overcome  ? 


AND   AGRICULTURE. 


47 


rious  substance,  and  this  result  would  often  be 
aided  by  supplying  an  additional  quantity  of 
lime. 

Good  and  fertile  land  will  soon  become  poor 
and  unproductive,  if  the  same  kind  of  crops  are 
raised  on  it  year  after  year.  If  wheat  or  oats 
be  raised  season  after  season  from  the  same  soil, 
it  will  after  a  while  be  unable  to  produce  a  good 
crop  of  either  of  these  grains. 

The  reason  why  a  succession  of  crops  of  the 
same  kind  will  impoverish  good  land,  and  make 
it  unproductive,  is  easily  seen.  They  take  "^^f 
from  the  soil  certain  substances  in  large  amounts, 
until,  after  a  while,  the  soil  can  no  longer  fur- 
nish the  substances  required  by  the  plants. 


Inorganic  Substances. 

Potash  and  Soda,    .   . 

Lime, 

Magnesia, 

Oxide  of  iron,  .  .  . 
Oxide  of  manganese,  . 
Phosphoric  acid,  .  . 
Sulphuric  acid,  .   .   . 

Silicia, 

Parts, 


Wheat. 

Oats. 

•Barley. 

Rye. 

37.72 

19.12 

20.70 

37.21 

1.93 

10.41 

3.36 

2.92 

9.60 

9.98 

10.05 

10.13 

1.86 

5.08 

1.93 

0.82 

trace 

1.25 

trace 

trace 

49.32 

46.26 

40.63 

47.29 

0.17 

0.26 

1.46 

3.07 

21.99 

0.17 

100.00 

98.87 

98.92  100.00  1 

Questions  —  What  is  the  effect  of  continually  raising  the 
«ame  crops  on  a  piece  of  land  ?  Why  does  a  succession  of 
the  same  crop  impoverish  the  soil  ? 


48  CHEMISTRY,    GEOLOGY 

Crops  of  grain  rapidly  exhaust  the  soil  of 
phosphoric  acid,  magnesia,  potash,  and  soda,  as 
will  be  seen  by  looking  at  the  table  showing  the 
constituents  of  the  inorganic  part,  or  ash,  of 
wheat,  oats,  barley,  and  rye. 

Unless  phosphoric  acid,  magnesia,  potash,  and 
soda,  be  constantly  supplied  in  the  form  of  ma- 
nure, it  will  be  seen  that  successive  crops  of 
grain  must  soon  take  up  all  those  substances  the 
soil  contained,  and  thereby  render  it  incapable 
of  producing  further  crops. 

The  phosphoric  acid  may  be  supplied  to  the 
soil  by  the  addition  of  bone-dust,  guano,  or 
other  substances  containing  an  abundance  of 
phosphorus.  Common  salt  will  supply  soda 
and  a  little  magnesia,  and  wood-ashes  will  give 
some  potash.  Bones  also  furnish  lime  to  the 
soil,  a  substance  which  oats  require  in  pretty 
large  quantity. 

If  the  crops  raised  are  always  carried  away 
from  the  soil,  and  their  inorganic  elements  are 

Questions.  —  Of  what  substances  do  grain  crops  most 
rapidly  rob  the  soil  ?  How  may  the  impoverishment  of  the 
soil  be  prevented  ?  What  substances  will  yield  phosphorus 
to  the  soil  ?  How  may  soda,  magnesia,  and  potash,  be  sup- 
plied ?    Do  bones  supply  anything  besides  phosphorus ' 


AND    AGRICULTURE.  49 

not  artificially  supplied,  the  best  land  will  soon 
become  poor.  Each  crop  robs  the  soil  of  a  cer- 
tain quantity  of  its  substance ;  and,  of  course,  if 
the  farmer  annually  takes  away  these  substances 
from  his  land  in  his  crops,  and  never  makes  good 
the  loss  by  new  additions,  he  must  expect  his 
farm  soon  to  be  run  out. 

By  the  addition  of  manures  containing  the 
substances  the  crop  takes  from  the  soil,  its  pro- 
ductiveness may  be  made  permanent.  Manures 
should  be  supplied  of  the  right  kind,  in  appro- 
priate quantities,  and  at  the  proper  periods  of 
the  year ;  and  there  should  always  be  more  in 
quantity  of  the  substances  taken  up  by  the  crops, 
than  they  annually  consume. 

Many  farmers  are  afraid  of  the  cost  of  ma- 
nures, and  so  they  always  have  unproductive 
land  and  unprofitable  crops.  Others  supply  an 
abundance  of  manure,  but  it  often  is  not  the 
kind  the  land  needs,  and  is  just  so  much  waste : 
whilst  others  render  the  manure  they  do  use  of 

Questions.  —  Why  does  the  removal  of  crops  from  the 
land  impoverish  it  ?  How  may  the  productiveness  of  land 
be  maintained  ?  What  kind  of  manures  should  be  used  ? 
Should  the  manures  contain  more  of  a  given  substance  than 
the  crop  consumes  ? 

5 


50  CHEMISTRY,    GEOLOGY 

but  little  value,  by  their  careless  mode  of  prepar- 
ing or  keeping  it. 

ON    THE    APPLICATION     OF    MANURES    TO     THE 
SOIL. 

Everything  that  supplies  food  to  plants  through 
the  soil  may  be  called  a  manure.  There  are 
three  distinctive  kinds  of  manures:  vegetable, 
animal,  and  mineral.  Vegetable  manures  are 
those  parts  of  plants  that  are  buried  in  the  soil, 
which  they  enrich  by  the  process  of  decomposi- 
tion or  rotting,  whereby  the  substances  of  which 
they  are  composed  are  returned  to  the  land. 
Grass,  clover,  straw,  hay,  potato-tops,  corn- 
stalks, etc.,  are  amongst  the  most  valuable 
No.  16.  of  the  vegetable  ma- 

nures. Sometimes  a 
crop  of  green  grass  is 
used  as  a  manure,  by 
being  ploughed  into 
the  soil.  When  grass 
is  to  be  ploughed  up  for  manure,  the  sods  should 
not  be  deeply  buried  ;  they  should  be  left  so  near 

Questions.  —  What  is  a  manure  ?  How  many  kinds  of 
manure  are  there  ?  Of  what  do  vegetable  manures  consist } 
Should  green  crops  be  deeply  ploughed  in  for  manures? 


AND   Ab  IICULTURE.  51 

the  surface  that  the  roots  of  the  young  grain 
may  be  enabled  to  feed  upon  the  decaying  grass. 
Clover,  buckwheat,  rape,  rye,  and  sometimes 
young  turnips,  are  ploughed  in  green,  as  ma- 
nure. 

Green  crops  should  be  ploughed  into  light  and 
sandy  soils,  and  such  as  are  poor  in  vegetable 
matter.  Sea- weed  is  also  a  very  valuable  ma- 
nure, adding  largely  to  the  richness  of  the  soil. 
It  not  only  supplies  vegetable  matter,  but  saline 
substances.  It  is  either  spread  over  the  land, 
where  it  rots,  or  it  is  first  made  into  a  compost. 
Marl  and  shell-sand,  mixed  with  sea- weed,  and 
turned  over  twice  or  thrice  before  application, 
makes  a  very  excellent  compost  for  light  soils. 
Potato  and  turnip  tops,  w^hen  the  roots  are  dug, 
make  a  good  manure  if  ploughed  in,  especially  if 
grain  is  to  be  the  next  crop.  By  pulling  off  the 
blossoms  from  the  pot  to-stalks,  they  may  be 
kept  green  until  the  potatoes  are  dug  out, 
and  thus  the  yield  of  green  manure  is  much 
increased. 

Questions.  — Why  should  he  sods  be  left  near  the  sur- 
fiice?  Name  other  green  ci  'ps  which  are  ploughed  in  as 
manures.  For  what  kind  of  ands  are  green  crops  the  best 
manure  i  Is  sea-weed  a  good  lanure  ?  How  may  the  quan- 
tity of  potato-tops  be  increases  for  manure  ? 


o 


62  CHEMISTRY,    GEOLOGY 


Hay  is  returned  to  the  land  in  the  form  of 
the  dung  of  the  animals  by  which  it  has  been 
used  as  food.  Straw  is  sometimes  cut  and  mixed 
in  feed,  and  thus  becomes  manure ;  but  it  is 
generally  returned  to  the  soil  trodden  amongst 
the  litter.  Where  few  cattle  are  kept,  straw  is 
rotted  with  water  and  a  little  cow-dung,  and  put 
into  the  land  in  a  half-fermented  state.  For 
light  lands,  the  straw,  etc.,  should  be  well  rot- 
ted ;  but  for  heavy  lands  the  manures  are  best 
applied  half-fermented,  because  then  they  help 
to  keep  the  soil  light  and  porous. 

Rape-cake  and  rape-dust  are  also  applied  as 
manures  to  turnips  and  potatoes,  thereby  saving 
the  whole  or  a  part  of  the  common  farm-dung. 
It  is  also  sometimes  applied  advantageously  as  a 
top-dressing  to  spring  wheat.  Rape-cake  is  the 
substance  that  remains  when  the  oil  is  squeezed 
out  of  the  seed ;  and  when  the  cake  is  dried  and 
crushed  it  becomes  rape-dust. 

The  most  important  animal  manures  are  blood, 


Questions,  —  How  is  hay  returned  to  the  soil  as  a  ma- 
nure ?  How  is  straw  used  for  the  same  purpose  ?  What 
difference  should  there  be  in  vegetable  manures  for  light 
and  heavy  soils  ?  Is  rape-cake  useful  as  a  manure  ?  Ho¥» 
is  it  made  ?     How  is  it  applied  as  a  manure  ? 


AND   AGRICULTURE.  58 

flesh,  bones,  hair,  wool,  and  the  dung  and  urine 
of  animals.  Many  kinds  of  fish  are  also  much 
used  as  a  manure. 

Blood,  as  a  manure,  is  best  mixed  with  the 
general  refuse  of  the  manure-heap.  It  is  some- 
times dried,  and  applied  as  a  top-dressing,  or 
drilled  in  with  the  seed.  It  is  one  of  the  most 
powerful  fertilizers. 

The  flesh  of  dead  horses,  diseased  cows,  hogs, 
etc.,  and  dogs,  when  decomposed,  makes  a  very 
valuable  manure.  They  should  be  buried  in 
soil  to  which  saw-dust  or  marl  is  added,  or  be 
decomposed  by  the  action  of  oil  of  vitriol. 
Sometimes  lime  may  be  advantageously  added  to 
the  substances  to  undergo  decomposition,  whereby 
all  the  gases  disengaged  during  that  process  are 
absorbed  and  retained  for  use. 

Bones  are  broken  and  crushed  in  suitable 
mills,  and  sifted  into  various  degrees  of  fineness, 
from  a  coarse  dust  into  pieces  of  half-inch  or  inch 
in  size.     Bones  act  most  quickly  as  a  fertilizer 

(Questions.  —  What  are  the  most  important  animal  ma- 
nures ?  How  is  blood  applied  as  a  fertilizer  ?  How  is  flesh 
best  prepared  for  manure  ?  How  are  bones  prepared  as  a 
fertilizer  ?     How  do  bones  act  most  quickly  as  a  manure  ? 

5» 


54 


CHEMISTRY,    GEOLOGY 


when  reduced  into  powder  ;  but  they  are  sooner 
exhausted  than  when  used  in  a  larger  form. 

Bones  are  best  adapted  for  light  or  well- 
drained  lands,  and  may  take  the  place  of  the 
whole  or  part  of  the  farm-yard  manure.  When 
they  are  so  used,  it  is  well  to  combine  them 
with  wood-ashes,  and,  thus  mixed,  they  may  be 
drilled  in  with  turnip  or  other  seed. 

Crops  of  turnips  do  best  when  manured,  alter- 
nate seasons,  with  bones  and  the  compost  of  the 
farm-yard. 

Bone-dust  may  be  profita- 
bly applied,  as  a  manure,  to 
grass  lands  that  have  been 
long  pastured  by  growing 
stock;  nor  is  the  wetness  of 
the  soil  an  objection  to  their 
use. 

Bones  consist  of  a  peculiar 
earth,  the  phosphate  of  lime, 
and  glue,  or  gelatine.  If  you 
burn  a  thin  piece  of  bone  in 


Fig.  17. 


Questions.  —  For  what  lands  are  bones  best  adapted  for 
manure  ?  How  may  they  be  used  ?  How  do  turnips  thrive 
best  ?  To  what  other  purpose  may  bone  manure  be  applied  ? 
Of  what  are  bones  composed  ? 


AND   AGRICULTURE.  65 

the  flame  of  a  lamp,  the  organic  part,  or  the 
gelatine,  is  consumed,  and  the  inorganic  part,  or 
the  phosphate  of  lime,  remains  unburned.  The 
gelatine  may  be  also  to  a  large  extent  removed 
by  boiling  in  successive  portions  of  water.  By 
boiling  under  a  pressure  of  steam,  all  the  gela- 
tine may  be  dissolved  out. 

The  glue  or  gelatine  of  bones  is  a  very  good 
and  powerful  manure ;  and  materially  assists  in 
advancing  the  growth  of  the  turnip  crop. 

The  bone-earth,  or  the  part  left  unconsumed 
by  fire,  contains  phosphoric  acid  and  lime.  The 
phosphorus  and  lime  are  both  valuable  manures, 
as  may  be  seen  on  reference  to  the  table,  page  47, 
which  shows  how  much  of  these  substances  some 
crops  annually  take  from  the  land. 

Bones  are  essentially  requisite  on  old  dairy 
lands.  Milk  and  cheese  both  contain  bone-earth ; 
and,  unless  the  soil  is  replenished  with  phosphoric 
acid  and  lime,  it  soon  becomes  poor  and  unpro- 
ductive,   or  only   capable   of   growing  grasses 

Questions.  —  If  you  burn  a  bone,  what  is  consumed? 
What  remains  unconsumed  ?  What  is  the  effect  of  the  glue 
or  gelatine  of  bones?  Of  what  is  bone-earth  composed? 
Are  they  valuable  manures  ?  Why  are  bones  requisite  on 
old  dairy  lands  ? 


56  CHEMISTRY,    GEOLOGY 

"which  require  a  small  quantity  of  those  sub- 
stances. 

In  every  ten  gallons  of  milk  there  is  about 
half  a  pound  of  bone-earth ;  hence  a  cow  which 
gives  twenty  quarts  a  day  takes  from  the  soil 
about  two  pounds  of  phosphate  of  lime  every 
week.  To  restore  these  two  pounds  of  phos- 
phoric acid  and  lime  to  the  soil,  three  pounds  of 
bone-dust  are  required ;  and,  by  the  process  of 
decomposition,  the  land  obtains  the  phosphoric 
acid  and  lime  of  which  the  inorganic  part  of  the 
bones  was  made. 

For  manure,  bones  are  sometimes  dissolved  in 
sulphuric  acid;  and,  for  this  purpose,  equal 
weights  of  bone-dust  and  acid  are  mixed  together, 
and  allowed  to  stand  until  the  acid  has  chem- 
ically decomposed  the  substance  of  the  bones. 

By  thus  preparing  the  bones  for  manure,  the 
substances  of  which  they  are  composed  are  veiy 
minutely  divided ;  they  are,    on   this   account, 

Questions.  —  How  much  bone-earth  in  every  ten  gallons 
of  milk?  How  much  bone-earth  is  taken  from  the  soil 
every  week  by  a  cow  giving  twenty  quarts  of  milk  a  day  ? 
How  much  boue-dust  is  required  to  make  good  to  the  soil 
what  it  thus  loses  ?  Are  bones  applied  as  manure  in  any 
other  form  ?  What  is  the  advantage  of  thus  preparing  the 
bones  ? 


AND    AGRICULTURE.  57 

more  readily  taken  up  by  the  roots  of  the  plants, 
because  the  acid  has  already  done  what  must 
otherwise  have  been  effected  in  the  soil;  for, 
until  the  bones  are  decomposed,  they  are  of  no 
value  as  a  manure.  Another  advantage  is,  a 
smaller  quantity  produces  an  equal  effect  on  the 
crop. 

Sometimes  another  mode  is  adopted.  A  given 
weight  of  bone-dust  and  an  equal  weight  of  sul- 
phuric acid  are  mixed,  and  to  this  thirty  times  the 
bulk  of  water  is  added.  This  mixture  may  be 
applied  to  the  soil  from  a  common  watering-cart ; 
or  sufficient  powdered  charcoal,  peat,  saw-dust 
or  soil,  may  be  added  to  take  up  all  the  fluid, 
when  the  compost  may  be  applied  in  the  usual 
way.  The  charcoal  is  a  good  addition ;  but  the 
peat  and  the  saw-dust  are  gradually  converted 
into  carbon.. 

Hair  is  not  much  used  as  a  manure,  because 
of  its  expense.  The  sweepings  of  our  hair-cut- 
ters' rooms,  now  all  wasted,  might  be  collected 
and  most  profitably  used. 

Questions.  —  Is  there  any  other  mode  of  preparing  bones 
for  manure?  Describe  how  this  preparation  may  be  ap- 
plied. May  this  mixture  be  made  into  solid  compost? 
How  ?  Is  hair  much  used  as  a  manure  ?  Is  not  much  hair 
wasted  ? 


58  CHEMISTRY,    GEOLOGY 

Woollen  rags,  cut  into  small  pieces  and  mixed 
with  earth,  make  a  very  useful  compost;  and 
they  are  much  more  effective  if  first  decomposed 
by  sulphuric  acid. 

The  contents  of  privies,  and  the  dung  of  horses, 
cows,  sheep,  pigs,  and  birds,  are  all  employed  as 
manures.  Night-soil,  now  manufactured  into  an 
article  caWed  poud?'ette,  and  birds'  dung  (guano), 
are  the  most  valuable  as  fertilizers :  next,  pigs' 
dung,  and  lastly  that  of  cows. 

Night-soil  is  most  valuable  as  a  manure,  be- 
cause men  live  upon  a  mixed  animal  and  vege- 
table diet,  whereby  their  excrement  is  richer  in 
those  substances  which  plants  take  up  from  the 
soil.  The  dung  of  horses  is  more  valuable  than 
that  of  cows,  because  the  horse  makes  compar- 
atively little  water.  Pigs'  dung  is  by  some 
thought  objectionable,  as  it  has  been  supposed 
to  give  a  disagreeable  taste  and  smell  to  crops 
raised  from  it;   an  opinion,  we  think,  without 

Questions,  — How  are  woollen  rags  best  used  a  manure  ? 
Name  some  other  sources  of  manures.  What  is  manufac- 
tured night-soil  called  ?  What  is  guano  ?  Why  is  night- 
soil  most  valuable  as  a  manure  ?  "Why  is  horse  dung  a  better 
fertilizer  than  that  of  cows?  Why  has  pig  dung  been 
deemed  objectionable  ? 


AND  AGRICULTURE.  59 

foundation.     It  \&  always  better  mixed  into  a 
compost  with  other  manures  than  used  alone. 

Cow  dung  is  colder,  and  less  easily  decom- 
posed, because,  by  the  large  quantity  of  urine 
voided  by  the  cow,  most  of  the  excrementitious 
salts  are  carried  away.  This  defect  may  be  rem- 
edied by  the  addition  of  wood-ashes,  or  quick- 
lime, well  turned  into  the  heap,  whereby  the 
process  of  decomposition  is  greatly  hastened,  and 
the  manure  much  improved. 

The  mixed  dung  of  animals  dif-         rig.  is. 
fers  from  the  food  they  consume, 
in   containing  less    carbon    and 
more  nitrogen  than  the  food  eaten. 
The  carbon  is  thrown  off  by  the 
lungs  in  the  act  of  breathing,  in 
the  form  of  carbonic  acid  gas.     A 
man  throws  off  from  his   lungs 
about  half  a  pound  of  carbon  daily ;  and  a  horse 
or  a  cow,  eight  or  ten  times  as  much.     You  may 
see  the  carbonic  acid,  as  it  is  thus  thrown  off  by 

Questions.  —  How  is  pig-dung  best  used  ?  Why  is  cow 
dung  less  valuable  as  a  manure  ?  How  may  it  be  much 
improved  ?  Wherein  does  the  dung  of  animals  differ  from 
their  food?  What  becomes  of  the  carbon?  How  much  carbon 
does  a  man  throw  off  daily  ?     How  much  a  horse  or  cow  ? 


60  CHEMISTRY,    GEOLOGY 

the  lungs,  bj  a  very  simple  experiment.  Put  a 
piece  of  lime  into  a  pitcher  of  water,  and  let  it 
stand  a  day.  Take  some  of  the  clear  lime-water, 
put  it  into  a  tumbler,  and  pass  the  air  from  the 
lungs  through  it,  by  breathing  through  a  straw 
or  a  clean  pipe-stem.  In  a  little  while,  the 
water,  which  was  clear,  becomes  milky,  and  soon 
carbonate  of  lime  (chalk)  falls  to  the  bottom^ 
(See  Fig.  18.) 

The  water  contained  a  clear  solution  of  lime  \ 
the  lime  combined  with  the  carbonic  acid  in  the 
air  breathed  from  the  lungs,  and  formed  the  car- 
bonate of  lime ;  and,  as  that  will  not  dissolve  m 
water,  it  is  visible  to  the  eye,  and  soon  settles 
on  the  bottom  of  the  tumbler. 

Almost  all  the  nitrogen  contained  in  the  food 
is  retained  in  the  excrements  of  animals,  mixed 
with  a  smaller  quantity  of  carbon  than  they  took 
in  with  their  food ;  and  the  larger  proportion  of 
nitrogen  contained  in  the  dung  of  animals  is  one 
of  the  causes  of  their  greater  value  as  a  manure. 

The  nitrogen,  in  the  process  of  the  decompo- 

Questions.  —  How  can  you  prove  that  carbonic  acid  is 
thrown  out  in  the  act  of  breathing  ?  What  becomes  of  the 
nitrogen  contained  in  the  food  of  animals  ? 


AND   AGRICULTURE.  61 

sition  of  manures,  is  changed  into  ammonia,  which 
is  a  kind  of  air,  or  gas,  having  a  very  strong 
smell.  The  hartshorn  of  the  shops  is  only  water 
holding  ammoniacal  gas  in  solution  ;  and  smell- 
ing-salts owe  their  pungency  to  the  ammonia 
they  contain. 

The  ammonia  is  produced  by  the  fermentation 
of  compost  or  manure  heaps,  and  is  the  cause  of 
the  smell  perceived  in  stables  and  privies.  It  is 
a  very  valuable  agent  in  manures,  and  should  be 
kept  from  flying  off  by  the  addition  of  sulphate 
of  lime,  whereby  the  volatile  carbonate  of  am- 
monia is  transformed  into  the  non-volatile  sul- 
phate of  ammonia. 

You  may  detect  the  presence  of  ammonia  by 
dipping  a  feather  into  vinegar  and  holding  it 
over  the  dung-heap  in  the  stable,  when,  if  am- 
monia is  forming,  it  will  be  seen  in  white  fumes 
around  the  feather. 

Another  method  will  enable  you  to  see  the 
ammonia.     Dip  a  feather  into  strong  vinegar, 

Questions. — Into  what  is  nitrogen  changed  by  the  fer- 
mentation of  manures  ?  Describe  ammonia.  What  is  the 
cause  of  the  smell  of  stables  and  privies  ?  Should  the  am^ 
monia  be  retained  in  the  manure  ?  How  should  it  be  kept 
from  flying  off  ?    How  can  you  detect  ammonia  ? 

6 


62 


CHEMISTRY,    GEOLOGY 


and  hold  it  over  the 
mouth  of  a  bottle  con- 
taining hartshorn,  or  a 
strong  smelling-bottle ; 
the  white  fumes  will  be 
seen,  showing  that  am- 
monia, as  a  gas,  is 
escaping.  These  white 
fumes  are  the  ammonia 
(an  alkali)  combining 
with  the  vinegar  (acetic 
acid).  The  white  fumes  will  be  more  abundant 
if  a  glass  rod,  dipped  into  muriatic  acid,  be  used. 
Ammonia  is  composed  of  two  gases,  nitrogen 
and  hydrogen.  Fourteen  pounds  of  nitrogen  and 
three  pounds  of  hydrogen  make  seventeen  pounds 
of  ammonia. 

The  ammonia  contained  in  manure  is  dissolved 
by  the  water  contained  in  the  soil,  and  it  is  then 
taken  up  by  the  roots  of  the  plants.  In  the 
plant,  it  aids  in  the  formation  of  gluten,  and 
other  portions  of  its  substance  containing  ni- 
trogen. 

Qtiestions.  —  Of  what  is  ammonia  composed  ?  In  what 
proportions  ?  How  do  plants  obtain  the  ammonia  from  the 
soil  ?    Of  what  use  is  ammonia  in  the  plant  ? 


AND   AGRICULTURE.  63 

Thus  you  see  ammonia  is  a  very  important 
article  in  the  composition  of  manures ;  for  the 
growth  of  the  plant  demands  nitrogen,  which  it 
must  obtain  from  the  soil. 

Ammonia  exists  in  the  largest  quantity  in  the 
urine  of  animals,  especially  in  that  of  the  cow ; 
and  it  is  hence  of  importance  that  it  should  be 
preserved,  as  far  as  possible.  The  more  liquid 
portions  of  all  manures  should  also  be  saved, 
instead  of  being  allowed  to  run  to  waste,  or  to 
soak  into  the  ground  of  the  farm-yard. 

Every  farmer  should  have  a  cemented  tank, 
or  a  large  wooden  vat  or  cistern,  in  some  con- 
venient spot  in  the  farm-yard,  into  which  these 
liquid  manures  may  collect ;  and  they  should  be 
frequently  pumped  or  bailed  back  upon  the 
heaps  of  manure  or  compost,  thereby  aiding 
their  fermentation,  and  making  them  more  effi- 
cient as  fertilizers.  A  run  should  connect  the 
dung-heap  or  compost-bed  with  the  tank,  so  that 
the  soluble  portions  of  the  manure  carried  off  by 
rains  may  be  again  collected. 

Questions,  —  Why  is  ammonia  imporbxnt  in  manures? 
Where  is  the  largest  quantity  of  ammonia  found  ?  Ought 
these  fluids  to  be  saved  ?  How  can  the  farmer  save  them  ? 
Of  what  use  are  they  thrown  on  manure-heaps  ? 


64  CHEMISTRY,    GEOLOGY 

Another  great  advantage  of  the  tank  is,  that 
during  the  spring  and  summer  months  its  con- 
tents, after  fermentation,  and  diluted  with  once 
or  twice  its  bulk  of  water,  may  be  applied,  by 
the  watering-cart,  to  grass  land,  young  clover, 
or  any  other  young  crops. 

The  ammoniacal  liquor  of  the  gas-works, 
diluted  with  four  or  five  times  its  bulk  of  water, 
may  be,  where  attainable,  employed  in  the  same 
manner  and  for  the  same  purposes  as  the  liquid 
manure  of  the  farm-yard ;  or,  it  may  be  made 
into  a  compost  with  peat  and  vegetable  mat- 
ter. 

The  excrement  of  birds  is  a  most  valuable 
manure.  The  article  now  so  popular,  and  known 
as  guano,  is  the  excrement  of  sea-fowls,  which 
has  been  accumulating  for  ages  in  the  localities 
where  it  is  found.  Farmers  should  carefully 
collect  and  preserve  for  use  the  dung  of  hen- 
houses and  pigeon-cotes ;  they  make  a  very  effi- 
cient top-dressing  for  young  grain  crops,  and 
may  be  used,  wholly  or  in  part,  in  place  of  the 

Questions.  —  Has  the  tank  any  other  advantage?  To 
what  purposes  may  the  ammoniacal  liquor  of  gas-works  be 
applied  ?  What  is  guano  ?  Is  the  excrement  of  other  birds 
useful  as  a  manure  ? 


AND   AGRICULTURE.  65 

farm-yard  manure  ;  they  contain  a  large  quantity 
of  ammonia. 

These  manures  should  not  come  into  imme- 
diate contact  with  the  seed,  but  should  be  well 
mixed  with  a  suitable  quantity  of  earth. 

Quick-lime  should  never  be  mixed  with  guano, 
or  other  manures  containing  ammonia ;  because 
the  lime  sets  the  ammonia  free,  and  allows  it  to 
escape  into  the  atmosphere.  * 

Fig.  20.  You    may    easily 

be  satisfied  of  this 
fact.  Take  a  little 
f^K  \i  (K.^^^^^  \  slaked  lime,  and  mix 
it  with  a  small  quan- 
tity of  guano,  or  the 
excrement  of  pig- 
eons, etc.,  in  a  tea- 
cup. The  ammonia 
will  be  at  once  recognized  by  its  peculiar  smell ; 
and  you  may  see  it  by  holding  over  the  cup  ji 

Questions. — What  does  the  excrement  of  birds  contain 
in  large  quantity  ?  Should  they  be  applied  directly  to  the 
seed  ?  Why  should  not  lime  be  mixed  with  manures  con- 
taining ammonia  ?  How  can  you  prove  that  manures  lose 
their  ammonia  if  mixed  with  lime  ? 

6* 


66  CHEMISTRY,    GEOLOGY 

feather  dipped  into  strong  vinegar,  when  the  white 
fumes  will  be  apparent.  The  same  result  is 
attained  if  quick-lime  is  mixed  with  sal-ammo- 
niac ;  and  a  similar  result  is  caused  if  lime  is 
mixed  with  the  liquid  manures  of  the  farm-yard. 

For  turnips  and  potatoes,  guano  should  be 
mixed  with  an  equal  weight  of  the  common  farm- 
yard manure  ;  because,  alone,  it  does  not  contain 
sufficient  organic  matter  to  maintain  the  land  in 
its  most  productive  state. 

A  fair  proportion  for  grain  and  corn  crops  is 
about  two  hundred  weight  to  the  acre  as  a  top- 
dressing  ;  and  for  potatoes  or  turnips  about  the 
same  quantity  when  mixed  with  half  the  amount 
of  common  manure,  or  about  three  hundred 
weight  of  the  mixture,  per  acre. 

Where  fish  are  abundant,  they  may  be  very 
profitably  used  as  a  fertilizer.  They  are  best 
made  into  a  compost  with  marl  and  earth,  and 
the  heaps  should  be  turned  or  worked  over  two 

Questions. — Why  should  guano,  for  some  crops,  be 
mixed  with  common  manures  ?  How  much  guano  to  the 
acre  is  needed  for  grain  and  corn  crops  ?  How  much  when 
mixed  with  an  equal  weight  of  common  manure,  for  pota- 
toes and  turnips?  Are  fish  useful  as  a  manure?  How 
should  they  be  prepared  ? 


AND   AGRICULTURE.  67 

or  three  times,  before  use.  Fish  ought  never  to 
be  exposed  on  the  surface  of  the  ground ;  their 
exhalations,  during  decomposition,  are  very  offen- 
sive, and  prejudicial  to  health. 

Amongst  mineral  manures,  the  most  valuable 
are  nitrate  of  soda,  sulphate  of  soda  (common 
glauber  salts),  sulphate  of  lime  (gypsum),  kelp, 
wood-ashes  (potash),  and  lime. 

Nitrate  of  soda  is  a  white,  saline  (salt-like) 
substance,  found  as  an  abundant  natural  product 
in  some  parts  of  Peru.  It  is  usefully  applied, 
as  a  top-dressing,  to  grass  lands  and  young  grain 
crops.     (See  Appendix,  24.) 

It  contains  nitric  >  acid  and  soda ;  fifty-four 
pounds  of  nitric  acid  and  thirty-one  pounds  of- 
soda  form  eighty-five  pounds  of  nitrate  of  soda. 

Nitric  acid  is  an  intensely  sour  and  corrosive 
fluid,  commonly  known  as  aquafortis.  It  con- 
sists of  two  gases,  nitrogen  and  oxygen ;  four- 
teen pounds  of  nitrogen  and  forty  pounds  of  oxy- 
gen make  fifty-four  pounds  of  nitric  acid.    Thus 

Questions. — Why  should  not  fish  be  exposed  on  the  sur- 
face of  the  ground  ?     What  are  the  most  valuable  mineral 
manures  ?     Where  ia  nitrate  of  soda  found  naturally  ?    Of 
what  is  it  composed  ?    What  is  nitric  acid  ?     Of  what  com 
posed  ?    In  what  proportions  ? 


68  CHEMISTRY,    GEOLOGY 

you  see  that,  although  so  corrosive  and  destruc- 
tive to  life,  it  contains  the  same  elements  as  the 
air  we  breathe,  but  mixed  in  different  propor- 
tions. 

The  nitrate  of  soda,  by  decomposition,  yields 
nitrogen  and  soda  to  the  growing  crops.  About 
one  and  a  half  hundred  weight  may  be  spread 
over  each  acre. 

Sulphate  of  soda  is  commonly  known  as  glau- 
ber  salts.  It  is  composed  of  sulphuric  acid  and 
soda.  Sulphuric  acid  is  sulphur  combined  with 
oxygen.  It  is  often  advantageously  applied  as 
a  top-dressing  to  grass  lands,  turnips,  and  to 
young  potato-plants.  Seventy  pounds  of  dry 
sulphate  of  soda  contain  forty  pounds  of  sul- 
phuric acid  and  thirty-jne  pounds  of  soda. 

Common  salt  is  a  combination  of  soda  and 
muriatic  acid,  the  acid  commonly  known  as  spir- 
its of  salt.  It  may  be  applied  as  a  top-dressing, 
or  mixed  with  the  common  manure  of  the  yard, 
or  in  solution  in   the   water   used   for  slaking 

Questions,  —  What  does  nitrate  of  soda  yield  to  the 
soil  ?  Of  what  is  the  sulphate  of  soda  composed  ?  For  what 
is  it  useful  as  a  manure  ?  What  are  the  proportions  of  the 
components  of  sulphate  of  soda  ?     Of  what  is  common  salt 


AND    AGRICULTURE.  69 

quick-lime.  It  is  most  beneficial  in  localities  dis- 
tant from  the  sea,  or  where  the  land  is  sheltered 
from  the  winds  by  high  hills.  Near  the  sea- 
shore salt  is  never  needed,  because  the  w^inds 
carry  with  them,  in  passing  over  the  sea,  no 
small  portion  of  the  spray,  sprinkling  it  over  the 
soil  to  a  distance  of  many  miles  from  the  sea- 
coast. 

Gypsum,  or  plaster  of  Paris,  is  a  white  sub- 
stance, composed  of  sulphuric  acid  and  lime. 
Forty  pounds  of  sulphuric  acid  and  twenty-eight 
and  one-half  pounds  of  lime  make  sixty-eight 
and  one-half  pounds  of  burned  gypsum.  The 
same  proportions  of  acid  and  lime,  with  eighteen 
pounds  of  water,  compose  the  unburnt  gypsum. 
Native  gypsum  loses,  by  calcination,  about  twen- 
ty-one pounds  of  water,  and  becomes  burned 
gypsum. 

All  saline  (salt-like)  substances  should  be 
applied  to  the  soil  in  still  weather,  to  insure  their 
being  equally  spread ;  and  immediately  before  or 
after  a  rain,  that  they  may  be  readily  dissolved. 

Questions. — Where  is  salt  most  xxsefiilly  applied  ?  Of 
what  is  plaster  of  Paris  composed  ?  In  what  proportions  ? 
What  is  the  diflference  between  burned  and  unburned  gyp- 
sum ?    When  ought  salts  to  be  applied  to  the  soil  ? 


70  CHEMISTRY,    GEOLOGY 

Saline  substances  are  often  more  advanta- 
geously employed,  as  manures,  in  a  mixed  state, 
than  separately.  A  mixture  of  nitrate  and  sul- 
phate of  soda  has  been  found  to  produce  a  muclj 
more  beneficial  result  than  the  same  weight  of 
either  of  them  would  have  efiected ;  and  a  mix- 
ture of  common  salt  and  gypsum  will  do  more 
good  to  a  crop  of  beans  than  an  equal  weight  of 
either  of  the  articles  separately  applied. 

Kelp  is  the  ashes  of  sea- weeds  ;  they  contain 
an  oxide  of  sodium,  or  soda.  When  attainable 
in  large  quantities,  they  are  a  valuable  manure 
as  a  top-dressing  to  grass  lands ;  and,  mixed 
with  common  manure,  it  is  of  great  advantage  to 
crops  of  turnips  and  potatoes. 

Wood-ashes  contain  potash,  a  combination  of 
oxygen  with  potassium.  They  are  usefully 
applied  to  grass  lands,  destroying  the  mosses 
which  impede  the  growth  of  the  grass,  and  ren- 
dering it  much  more  thrifty  and  luxuriant. 
They  produce  the  same  effect  upon  young  grain 
and    potatoes.     Mixed  with  bones,    rape-dust, 

Questions. — Are  salts  best  applied  mixed,  or  alone? 
What  is  kelp  ?  Of  what  composed  ?  For  what  is  it  valuable 
as  a  manure  ?  Of  what  do  wood-ashes  consist  ?  What  is 
their  effect  upon  the  land  ? 


AND   AGRICULTURE.  71 

guano,  and  other  manures,  thej  make  a  very 
useful  compost. 

Limestone  consists  of  calcium  d?nd  oxygen ;  it 
is  an  oxide  of  the  metal,  calcium.  In  fifty 
pounds  of  limestone  we  find  twenty-eight  pounds 
of  lime  and  twenty-two  pounds  of  carbonic  acid. 
Limestone  is  hence  called  the  carbonate  of  lime, 
and  is  found  in  several  varieties.  It  is  soft,  as 
chalk;  hard,  as  our  common  limetone;  some- 
times yellow,  as  in  magnesian  limestones ;  pure 
and  white,  as  seen  in  statuary  marbles ;  black, 
as  the  Derbyshire  black  marble, —  besides  other 
varieties. 

Marl  is  a  carbonate  of  lime,  often  in  the  form 
of  a  fine  powder,  and  usually  mixed  with  earthy 
matter.  Shell-sand,  or  broken  sea-shells,  is  car- 
bonate of  lime  mixed  with  a  small  quantity  of 
organic  matter. 

All  these  varieties  of  limestone,  or  carbonate 
of  lime,  may  be  profitably  applied  to  land,  either 
jis  a  top-dressing,  or  ploughed  or  harrowed  into 
arable  fields.     They  are  most  useful  on  sour. 

Questions.  — What  is  limestone  ?  What  are  the  propor- 
tions of  carbonic  acid  and  lime  ?  What  is  limestone  called  ? 
Name  some  of  the  varieties  of  carbonate  of  lime.  How  may 
carbonate  of  lime  be  applied  to  soils  ? 


72 


CHEMISTRY,    GEOLOGY 


Fig.  21. 


coarse,  mossy  grass-lands ;  and  in  large  quanti- 
ties on  peaty  soils,  or  those  containing  an  excess 
of  organic  matter. 

Mixed  with  earth  or  vegetable  matter,  or  with 
animal  substances,  as  fish,  whale-blubber,  etc., 
they  will  often  be  found  a  very  useful  compost. 
If  you  want  to  ascertain 
whether  a  soil  or  substance 
contains  lime,  you  may  pour 
upon  a  small  quantity  of  it  vin- 
egar, or  dilute  muriatic  acid. 
If  lime  is  present,  the  mixture 
will  froth  up,  or  effervesce. 
This  bubbling,  or  effervescence, 
is  caused  by  an  escape  of  the 
carbonic  acid  of  the  carbonate 
of  lime,  because  the  stronger 
acids  combine  with  the  lime, 
and  therefore  let  the  carbonic 
acid  free. 

You  may  easily  prove  this 
by  putting   a  little   marl,   or 


Questions.  —  On  what  lands  is  carbonate  of  lime  most 
dseful  ?  How  can  you  ascertain  if  a  soil  contains  lime  ? 
What  makes  the  frothing,  or  effervescence  ?  How  may 
you  know  that  carbonic  acid  gas  is  liberated  ? 


AND    AGRICULTURE. 


73 


ohalkj  into  a  wine-glass,  and  pouring  upon  it  a 
portion  of  vinegar,  or  dilute  muriatic  acid. 
That  carbonic  acid  gas  is  liberated,  you  may 
prove  by  bringing  a  lighted  taper  into  contact 
with  it,  when  it  will  be  extinguished. 

When  limestone,  or  the  carbonate  of  lime,  is 
burned  in  a  kiln,  the  carbonic  acid  is  driven  off 
by  the  heat,  and  the  lime  alone  remains.  It  is 
now  called  quick,  caustic,  or  hot  lime.  A  ton 
of  limestone  yields  about  eleven  and  a  quarter 
hundred  weight  of  quick-lime. 

If  water  is  added 


Fig.  22. 


It 


or 


into  a  fine  powder.     It  is 


to  quick-lime, 
rapidly  absorbs, 
drinks  it  in,  giving 
out  a  great  deal  of 
heat  in  the  form  of 
steam,  swelling  up 
largely,  and  at 
length  falls  down 
now  called  slaked 


Questions, — What  is  the  effect  of  biimiiig  limestone  in 
a  kiln?  What  is  it  called  after  burning?  How  much 
quick-lime  does  a  ton  of  limestone  yield  ?  What  is  the  effect 
of  adding  water  to  quick-lime  ?  What  is  it  called  after  thus 
falling  into  powder  ? 

7 


74  CHEMISTRY,    GEOLOGY 

lime,  and  is  no  longer  caustic,  or  hot.  The 
heat  produced  in  the  process  of  slaking  is  some- 
times so  great  as  to  set  fire  to  gunpowder  placed 
upon  a  drj  portion  of  the  mass,  and  a  cold 
baked  pie,  may  be  thoroughly  heated  by  being 
placed  upon  the  slaking  lime.  Occasionally  the 
heat  given  off  sets  fire  to  the  sod  with  which 
heaps  of  lime  are  sometimes  covered  in  the  field. 

One  ton  of  pure  quick-lime,  after  slaking, 
weighs  twenty-five  hundred  pounds,  the  ton  of 
lime  having  absorbed  and  retained  five  hundred 
weight  of  water. 

Quick-lime  falls  to  powder  gradually  if  ex- 
posed to  the  atmosphere,  because  it  absorbs  the 
water  contained  in  the  air. 

In  addition  to  the  water  from  the  atmosphere, 
quick-lime  absorbs  a  portion  of  its  carbonic  acid, 
and  is  again  changed  to  the  state  of  mild  carbon- 
ate. You  may  see  this  change  effected,  by  pour- 
ing a  little  clear  lime-water  into  a  tumbler-glass, 
which  will,  in  a  short  time,  be  covered  with  a 
thin  film  of  the  carbonate  of  lime. 

Questions,  —  What  change  has  the  quick-lime  undergone ! 
How  much  weight  does  a  ton  of  lime  gain  in  slaking  ?  Does 
lime  become  slaked  in  any  other  mode  ?  Does  the  air  effect 
any  other  change  in  quick-lime  ? 


AND   AGRICULTURE.  75 

When  lime  has  thus  repassed  into  the  state  of 
the  carbonate,  it  is  more  advantageously  applied 
to  the  land  than  before  it  was  burned,  because 
in  the  form  of  the  almost  impalpable  powder  into 
which  it  falls  by  being  air-slaked  it  can  be  more 
intimately  mixed  with  the  soil. 

The  quick  or  unslaked  lime  acts  most  prompt- 
ly upon  the  land,  but  the  quick  and  the  slaked 
or  mild  lime  both  act  in  the  same  manner ; 
they  supply  the  lime  which  all  plants  require  as 
a  portion  of  their  inorganic  food,  and,  by  com- 
bining with  the  acids  in  the  soil,  they  overcome 
its  sourness  and  coldness,  and  convert  the  vege- 
table matter  into  suitable  organic  food  for  the 
plants. 

Lime  should  always  be  applied  on  the  surface 
of  lands,  or,  at  most,  be  'only  just  harrowed 
under  the  surface. 

Quick-lime  should  be  applied  to  peaty  lands, 
to  heavy  clay  soils,  sour  arable  lands,  and  to 
soils  containing  much  vegetable  matter. 

Questions.  —  In  which  form  is  lime  most  advantageously 
applied  to  soils  ?  In  what  state  does  lime  act  most  promptly 
on  the  land  ?  How  does  lime  improve  the  soil  ?  What  effect 
has  lime  on  the  vegetable  matter  contained  in  the  soil  ?  How 
should  lime  be  applied  ?  To  what  lands  should  quick-lime 
be  applied  ? 


76  CHEMISTRY,    GEOLOGY 

An  equal  weight  of  lime  is  more  effective  upon 
drained,  or  dry  land,  than  upon  a  soil  which 
contains  an  excess  of  water.  Lime  should  be 
applied  to  the  soil  at  such  intervals,  and  in  such 
quantity,  as  ^  may  maintain  in  the  land  a  full 
supply  of  this  inorganic  and  most  necessary  ele- 
ment. The  application  of  lime  requires  repeti- 
tion, because  the  crops  take  up  and  carry  off  an 
amount  proportionate  to  their  wants,  annually ; 
because  some  portion  of  it  sinks  into  the  subsoil, 
and  is  there  useless ;  and,  lastly,  because  the 
rains  are  constantly  washing  some  portion  of  it 
out  of  the  land. 

THE   COMPOSITION   OF  CROPS. 

The  several  kinds  of  grain  mainly  consist  of . 
three  substances, —  starch,  gluten,  and  oil,  or  fkt 
In  one  hundred  pounds  of  wheat-flour  there  are 
about  fifty  pounds  of  starch,  ten  pounds  of 
gluten,  and  two  to  three  pounds  of  oil.  One 
hundred  pounds  of  oats  yield  about  sixty  pounds 

Questions.  —  Upon  what  land  is  lime  most  effective? 
How  often  should  the  soil  be  limed  ?  Why  does  the  lime 
need  to  be  repeated  ?  Of  what  do  the  several  kinds  of  grain 
chiefly  consist  ?  In  what  proportions  are  these  found  in  one 
hundred  pounds  of  wheat-flour  ?  In  one  hundred  pounds 
of  oats  ? 


AND   AGRICULTURE.  77 

of  starch,  eighteen  pounds  of  gluten,  and  six 
pounds  of  oil. 

The  principal  constituent  of  potatoes  and  tur- 
nips is  water.  Of  the  first,  one  hundred  pounds 
contain  seventy-five  pounds  of  water ;  and  of  the 
second,  one  hundred  pounds  yield  about  eighty- 
eight  pounds  of  water.  The  quantity  of  starch 
in  potatoes  is  about  fifteen  to  twenty  pounds  to 
the  hundred  pounds. 

The  proportions  of  the  several  substances  con- 
tained in  diiFerent  lots  of  the  same  kind  of  pro- 
duce will  often  be  found  to  vary  considerably. 
Some  samples  of  wheat  may  contain  more  gluten, 
some  varieties  of  oats  more  oil,  and  some  kinds 
of  potatoes  more  starch. 

We  have  already  seen  that  when  vegetables 
or  grain  are  burned  there  remains  a  small  quan- 
tity of  inorganic  matter,  or  ashes.  The  ashes 
contain  the  phosphates  of  potash,  soda,  lime,  and 
magnesia ;  they  also  contain  common  salt,  and 
some  other  saline  substances. 

Questions. — How  much  water  do  one  hundred  pounds 
of  potatoes  contain  ?  How  much  in  one  hundred  pounds  of 
turnips  ?  How  much  starch  in  one  hundred  pounds  of  pota- 
toes ?  Do  different  lots  of  the  same  kind  of  grain  always 
contain  the  same  proportion  of  starch,  fat,  &c.  ? 

7* 


78  CHEMISTRY,    GEOLOGY 

USE   OF   THE   PRODUCTIONS   OF  THE   SOIL. 

The  productions  of  the  soil  are,  to  a  large  ex- 
tent, designed  for  the  food  of  animals.  Animals 
must  obtain,  from  the  food  they  eat,  starch, 
gluten,  oil  or  fat,  and  saline  or  inorganic  matter, 
to  be  enabled  to  retain  health  and  life. 

You  will  recollect  that  we  proved  starch  to 
contain  carbon  and  water ;  and,  as  water  contains 
hydrogen  and  oxygen,  starch  contains  carbon, 
hydrogen,  and  oxygen.  Sugar  also  contains  the 
same  elements,  in  a  slightly-altered  form  of 
combination ;  and  in  gum  the  same  elements 
exist,  but  again  changed  in  their  proportions. 

Starch,  or  substances  containing  the  same 
elements,  must  form  a  part  of  the  food  of  ani- 
mals, to  supply  the  carbon  which  they  throw  off 
in  the  process  of  breathing. 

A  healthy  man  throws  off  from  his  lungs 
daily,  in  the  form  of  carbonic  acid  gas,  from  six 
to  eight  ounces  of  carbon ;  hence,  he  must  con- 

Questions. — What  is  the  great  purpose  of  the  produc- 
tions of  the  earth  ?  What  must  animals  obtain  from  their 
ibod  ?  Of  what  is  starch  composed  ?  Does  sugar  con- 
tain the  same  substances  as  starch  ?  Why  must  the  food 
of  animals  contain  starch,  or  similar  substances  ?  How 
much  carbon  does  a  man  throw  from  his  lungs  daily  ? 


AND   AGRICULTURE.  79 

sume  daily  some  substance  which  will  yield  that 
amount  of  carbon  to  his  system,  or  he  must  soon 
become  the  subject  of  impaired  health.  Fifteen 
ounces  of  starch  contain  about  seven  ounces  and 
three-quarters  of  carbon ;  so  that  his  food  must 
be  equal,  in  the  carbon  it  contains,  to  a  little 
more  than  fifteen  ounces  of  starch. 

The  carbonic  acid  gas  thrown  off  from  the 
lungs  is  diffused  in  the  atmosphere,  to  be  again 
taken  up  by  plants,  again  by  them  to  be  re- 
transformed  into  starch,  or  substances  similar  in 
composition  thereto.  Thus  you  see  how  beauti- 
fully, in  the  economy  of  nature,  the  processes 
of  reproduction  are  perpetuated.  The  same  car- 
bon is  again  and  again  transformed  by  the 
plant  into  starch,  and  by  the  animal  into  car- 
bonic acid.  The  animal  transforms  the  carbon 
into  carbonic  acid  gas,  by  a  process  of  combustion, 
necessary  to  keep  up  its  warmth ;  and,  in  the 
process  of  vital  combustion,  a  portion  of  the 
carbon  combines  with  a  portion  of  the  oxygen  of 

Questions.  —  How  much  starch,  or  its  equivalent,  must  a 
man  consume  daily  ?  What  becomes  of  the  carbonic  acid 
gas  thrown  from  the  lungs  ?  Is  the  same  carbon  again  and 
again  reproduced  and  consumed  ?  How  is  the  carbonic  acid 
gas  produced  by  the  animal  from  the  carbon  taken  in  his 
food? 


80 

air  taken  into  the  lungs,  and  forms  carbonic  acid 
gas. 

Gluten  must  form  a  part  of  the  food  of  animals, 
for  the  purpose  of  supplying  to  the  muscles,  or 
lean  part  of  the  body,  new  substance  to  make 
good  their  daily  loss.  Every  portion  of  the 
body  is,  by  a  similar  change  of  atoms,  constantly 
being  formed  anew :  and,  as  the  daily  added  por- 
tions have  fulfilled  their  purpose  in  the  struc- 
ture and  uses  of  the  several  organs  and  their 
adaptations,  they  are  again,  in  the  form  of 
excrementitious  matter  (sweat,  urine,  dung, 
carbonic  acid  gas,  etc.),  thrown  oflf  as  waste. 

Gluten  supplies  the  waste  of  muscles,  because 
the  gluten  of  plants  and  the  muscles  of  animals 
are  chemically  identical ;  that  is,  they  contain 
the  same  elements.  If  an  animal  eats  more 
gluten  in  its  food  than  is  required  to  supply  mus- 
cular waste,  the  excess  thereof  is  transformed 
into  fat. 

Food  which  contains  the  most  fatty  matter 
will  fatten  an  animal  in  less  time  than  those 

Questions. — Why  must  gluten  be  contained  in  the  food 
of  animals?  Why  does  gluten  supply  muscular  waste? 
What  becomes  of  any  excess  of  gluten  contained  in  the  food? 
What  kind  of  food  will  most  quickly  fatten  an  animal  ? 


AND   AGRICULTURE.  81 

varieties  which  are  deficient  in  that  substance, 
It  is  because  of  the  fatty  matter  contained  in 
oil-cake,  that  it  is  so  efficient  in  improving  the 
condition  of  stock  to  which  it  is  fed. 

Phosphate  of  lime,  and  other  saline  or  inor- 
ganic substances,  must  also  be  contained  in  the 
food  of  animals,  to  supply  the  constant  waste  of 
the  osseous  system  (the  bones),  the  salts  in  the 
blood,  etc. 

The  gluten  and  saline  matter  also  serve  an- 
other purpose  besides  supplying  the  constant 
waste  of  the  system;  they  daily  add  to  the 
weight  of  the  body  of  the  animal.  Hence  you 
see  why  it  is  that  a  growing  animal  requires 
much  more  of  these  kinds  of  food  than  one 
which  has  attained  his  growth.  The  full-grown 
animal  has  only  its  daily  waste  to  make  good ; 
but  the  grooving  animal  has  also  an  additional 
amount  of  new  substance  to  make  daily,  besides 
that  quantity  needed  to  supply  the  daily  waste 
of  its  system ;  if  it  did  not  do  this,  it  could 
never  become  larger,  or  increase  in  weight. 

Questions. — Why  should  the  food  of  animals  contain 
phosphate  of  lime,  and  other  inorganic  sub'stances  ?  What 
other  purpose  does  gluten  and  saline  substances  subserve  ? 
Why  does  a  growing  animal  require  more  of  those  substances 
than  a  full-grown  one  ? 


82  CHEMISTRY,    GEOLOGY 

If  the  same  weight  and  kind  of  food  be  given 
daily  to  a  growing  animal  and  one  which  has 
attained  its  growth,  the  dung  of  the  full-grown 
animal  will  contain  most  of  the  organic  and  in- 
organic substances  necessary  in  the  manure; 
because  the  growing  animal  must,  for  the  reason 
already  given,  retain  more  of  those  substances 
which  the  food  contained. 

It  is  for  this  reason  that  the  manure  made  by 
fattening  stock  is  much  more  valuable  than  that 
made  by  growing  stock.  The  former  take  up 
and  retain  only  the  oil  and  starch  the  food  con- 
tained, while  the  latter  take  up  and  retain  the 
greater  part  of  all  its  organic  and  inorganic  con- 
stituents. 

If  it  was  desired  to  make  the  largest  quantity 
of  beef  or  mutton  from  a  ton  of  oats  or  turnips, 
the  stock  should  be  kept  in  a  warm  and  sheltered 
place,  —  partially  secluded  from  the  light,  but 
where  they  could  obtain  good  and  wholesome 

Questions.  —  From  the  same  weight  and  kind  of  food,  will 
the  manure  made  by  a  growing  or  full-grown  animal  be 
most  valuable  J  Why  is  the  manure  made  by  a  full-grown 
aoimal  more  valuable  than  that  of  a  growing  animal? 
How  would  you  manage  to  make  the  most  beef  or  mutton 
out  of  a  ton  of  oats,  turnips,  or  other  food  ? 


AND   AGRICULTURE.  88 

air.  In  the  process  of  fattening  a  full-grown 
beast,  it  should  be  kept  warm,  fed  upon  oil-cake, 
oats,  or  corn,  with  abundance  of  turnips,  and  be 
allowed  to  take  only  limited  exercise. 

If  the  amount  of  manure  to  be  made  is  the 
object  of  the  farmer's  efforts,  then  his  stock 
should  be  kept  in  a  cooler  and  less  sheltered 
locality,  and  where  they  can  take  abundant 
exercise. 

When  the  farmer  is  anxious  to  obtain  the 
largest  quantity  of  milk,  his  cows  should  be  fed 
on  good  juicy  grass,  turnips,  corn  mashes,  and 
other  food  containing  abundance  of  water, —  and 
they  should  also  be  freely  supplied  with  water. 
But,  if  the  quality  of  the  milk  was  more  desira- 
ble than  the  quantity,  then  the  food  should  be 
principally  dry,  as  oats,  beans,  bran,  corn, 
clover-hay,  etc. ;  and  no  more  water  should  be 
given  than  necessary  for  health. 

If  the  milk  is  designed  for  butter,  then  the 
food  of  the  cow  should  be  rich  in  fatty  substance, 

Questions.  —  What  would  you  do  if  you  wanted  an  abun- 
dance of  good  manure  ?  What  would  you  do  to  obtain  the 
largest  quantity  of  milk  ?  What  course  would  you  pursue 
if  you  wanted  milk  of  the  best  quality  ?  What,  if  the  milk 
was  designed  for  butter  ? 


84 


as  oil-cake,  oats,  barley,  corn  meal,  good  sound 
hay,  and  a  moderate  quantity  only  of  turnips. 
But,  if  the  milk  is  designed  for  cheese,  then 
beans,  peas,  vetches,  or  clover-hay,  should  be 
fed,  because  those  articles  of  food  are  richer  in 
curd  substance. 

For  cattle  the  food  should  always  be  sweet 
and  fresh,  and  if  the  several  articles,  as  beans, 
turnips,  corn-meal,  etc.,  w^ere  first  boiled,  and 
then  allowed  to  become  cold  before  being  fed  to 
the  stock,  the  advantages  gained  would  more 
than  repay  the  additional  labor. 

The  food  of  hogs  is  better  given  slightly 
soured.  The  vegetable  refuse,  meal,  potatoes, 
etc.,  should  be  boiled  and  mashed  together,  and, 
^thus  mixed,  allowed  to  sour;  for  it  has  been 
found  that  more  and  better  pork  is  thus  made 
than  when  the  hogs'  food  is  fed  perfectly  sweet. 

Apples  are  an  excellent  food  either  for  hogs 
or  other  stock ;  and  they  would  be  thus  more 
profitably  used  by  the  farmer  than  converted 
into  cider. 

Questions.  —  What  course  would  you  pursue,  if  you  in- 
tended your  milk  to  be  made  into  cheese  ?  In  what  state  is 
the  food  of  cattle  best  given  ?  How  is  the  food  of  pigs  best 
given  ?  Why  should  the  food  of  pigs  be  cooked,  and  slightly 
soar  ?    Are  apples  a  good  article  of  food  for  stock  ? 


AND  AGRICULTURE.  85 

Stables,  cow-houses,  pig-styes,  hen-houses, 
etc.,  should  be  well  ventilated,  and  kept  clean  and 
sweet ;  and  they  ought  also  to  be  so  arranged  as 
to  be  kept  warm  and  dry  in  cold  and  wet 
weather.  The  farmer  can  keep  his  stock  through 
the  winter  on  one-third  less  food,  and  in  an 
equally  good  condition,  in  a  good,  warm^  com- 
fortable stable  or  out-house,  than  in  an  exposed, 
damp,  cold,  and  only  half-enclosed  out-house  or 
barn. 

Questions, — How  should  stables,  cow-houses,  etc.,  ht 
kept?  What  advantage  to  the  farmer  are  warm  stables, 
oow-houses,  etc.  ? 

3 


APPENDIX. 


1.  The  teacher  should  burn  a  piece  of  wood  or  straw 
in  the  flame  of  lamp  (Fig.  1),  and  explain  the  result. 

2.  Burn  a  piece  of  charcoal  before  the  class.  Notice 
the  dissimilarity  between  the  diamond  and  charcoal, 
though  chemically  the  same  body. 

3.  Provide  a  tall  glass  (Fig.  2)  and  a  piece  of  wire,  to 
the  end  of  which  a  small  bit  of  wax  taper  is  secured. 
Put  into  the  glass  a  few  shreds  of  zinc  or  iron  ;  pour 
upon  them  a  little  sulphuric  acid  diluted  with  two  or 
three  times  its  bulk  of  water.  Hydrogen  gas  forms 
rapidly.  Now  introduce  the  lighted  taper ;  an  explo- 
sion will  be  heard,  and  the  taper  is  extinguished.  Make 
the  gas  in  the  same  manner  in  a  vial  (Fig.  3) ,  and  show 
how  the  gas  burns.  Remove  the  cork,  and  put  the  taper 
into  the  vial.  It  is  instantly  extinguished,  and  the  gas 
ignited,  which  burns  at  the  mouth  of  the  bottle.  Slowly 
vnthdrawing  the  taper,  it  will  be  relighted  by  the  burn- 
ing hydrogen. 


88  APPENDIX. 

4.  Oxygen  gas  is  most  easily  prepared  by  mixing  to- 
gether equal  weights  of  chlorate  of  potash  and  black 
oxide  of  manganese,  putting  the  mixture  into  a  common 
Florence  flask,  and  applying  a  spirit-lamp  (see  Fig.  6). 
"With  a  piece  of  India-rubber  tube,  or  thin  lead  pipe, 
the  gas  may  be  collected  in  bottles,  as  seen  in  Fig.  8. 
When  filled,  they  may  be  corked  tightly.  Into  a  bottle 
of  oxygen  put  a  lighted  taper  (Fig.  4)  ;  show  the  bril- 
liancy of  the  flame.  In  the  same  manner  introduce  a 
smaU  piece  of  ignited  charcoal ;  and  next,  a  piece  of 
very  thin  iron  wire,  to  the  lower  end  of  .which  a  little 
bit  of  brimstone  is  secured,  and  ignited.  Show  how  the 
iron  is  consumed. 

Before  igniting  the  wire  weigh  it,  and  again  weigh 
the  mass  after  burning,  and  it  wiH  bo  found  to  have 
increased  in  weight,  by  combining  with  some  of  the  oxy- 
gen, forming  oxide  of  iron.  Fig.  5  shows  a  method 
of  exhibiting  some  of  the  efiects  of  oxygen,  without  any 
of  the  ordinary  apparatus.  Into  an  open  tube  a  small 
quantity  of  the  mixture  of  chlorate  of  potash  and  oxide 
of  copper  may  be  placed,  and  the  heat  of  a  lamp 
applied. 

5.  Nitrogen  may  be  prepared  by  mixing  sal-ammoniac 
with  half  its  weight  of  saltpetre,  both  in  fine  powder 
and  perfectly  dry,  and  heating  them  in  a  retort  over  a 
lamp.  The  gas  maybe  collected  as  in  Fig.  8.  Put  into 
a  bottle  of  nitrogen  a  lighted  taper  ;  its  flame  is  instantly 
extinguished,  and  the  gas  is  not  ignited,  as  was  the  hy- 
drogen. Nitrogen  is  also  formed  by  burning  phosphorus 
in  a  bottle  of  common  air;  the  oxygen  combines  with 


APPENDIX.  89 

the  phosphorus,  forming  phosphoric  acid,  and  the  nitro- 
gen alone  remains.  After  the  combustion  of  the  phos- 
phorus, the  water  will  have  risen  in  the  bottle  so  as  to 
fill  it  one-fifth,  the  quantity  of  oxygen  the  air  contained ; 
the  remaining  four-fifths  are  nitrogen. 

6.  Let  the  teacher  submit  to  the  class  specimens  of 
common  pear  lash ,  of  washing-soda,  of  quick-lime,  of  cal- 
cined magnesia,  oxide  (rust)  of  iron,  silicia,  as  flint  or 
quartz,  chlorine  gas,  a  bottle  containing  sulphuric  acid, 
phosphoric  acid  in  the  form  of  burnt  bones,  etc.  By 
this  mode  of  ocular  demonstration  his  class  will  soon 
become  acquainted  with  the  names  and  appearances  of 
these  several  articles. 

7.  Let  the  class  taste  a  dilute  solution  of  potash,  that 
they  may  recognize  the  alkaline  taste. 

8.  Exhibit  a  crystal  of  common  washing-soda,  and  let 
the  class  taste  it. 

9.  Let  the  class  look  at  and  cautiously  taste  a  piece 
of  quick-lime.  Pour  upon  it  a  little  water,  that  it  may 
fall  to  pieces.  Explain  the  word  slake,  as  applied  to 
this  process. 

10.  Describe  metals  as  bodies  having  more  or  less 
lustre,  weight  and  malleability.  Hammer  a  piece  of 
lead  and  a  piece  of  stone,  and  explain  the  difference  in 
the  result. 

8* 


90  A  rP  END  IX. 

11.  Let  the  teaclier  explain  the  meaning  of  oxidation. 
When  oxygen  unites  with  metals,  they  form  new  sub- 
stances, unlike  the  metal  from  which  they  were  formed. 
Put  a  little  red  lead  (oxide  of  lead)  into  the  bowl  of  a 
tobacco-pipe,  filled  with  finely-pulverized  charcoal ; 
then  let  the  pipe-head  ])ecome  red-hot,  by  placing  it  in 
the  fire,  or  in  the  [lame  of  a  spirit-lamp.  The  oxygen 
combined  with  the  lead  will  have  united  with  some 
of  the  cbarco.il,  forming  carbonic  acid  gas,  and  the 
lead  will  be  found  again  reduced  to  the  metallic  state. 

Next  put  a  little  of  the  red  oxide  of  mercury  into  a 
small  retort,  and  apply  a  spirit-lamp  (see  Fig.  8).  The 
oxygen  will  be  driven  off  by  the  heat,  and  the  bright 
fluid  metal,  mercury,  may  be  collected,  as  it  trickles 
down  the  beak  of  the  retort. 

12.  Put  a  little  black  oxide  of  manganese  into  a  Flor- 
ence flask,  and  pour  upon  it  a  portion  of  muriatic  acid, 
then  apply  the  heat  of  a  small  lamp.  The  chlorine  will 
be  set  free,  and  may  be  collected  in  bottles  filled  with  hot 
water,  as  seen  in  Fig.  8.  It  cannot  be  collected  over 
cold  water,  because  cold  water  rapidly  absorbs  the  gas. 
Chlorine  being  heavier  than  the  atmosphere,  it  may  be 
collected  in  bottles  filled  only  with  common  air,  by  at- 
taching the  India-rubber  tube  to  the  neck  of  the  flask, 
and  allowing  it  to  reach  the  bottom  of  the  bottle  to  be 
filled.  It  wiU  thus  gradually  force  the  air  out  of  the 
bottle,  a-nd  occupy  its  place.  Be  careful  not  to  inhale 
the  gas ;  and  experiments  with  chlorine  should  be  per- 
formed under  an  open  window,  or  in  the  open  air.  Put 
a  taper  into  a  bottle  of  chlorine  ;  it  is  instantly  extin- 


APPENDIX.  ftl 

guished.  Pour  it  from  a  bottle  upon  a  lighted  taper 
(Figs.  10  and  11),  proving  its  density  to  be  greater  than 
the  atmosphere.  Put  a  little  bit  of  phosphorus  into  a 
bottle  of  chlorine  ;  the  phosphorus  will  be  ignited,  and 
so  will  filings  of  zinc,  if  allowed  slowly  to  fall  into  a  bot- 
tle of  this  gas.  Show  its  bleaching  powers  by  its  action 
on  an  infusion  of  red  cabbage,  and  other  vegetable 
colors. 

13.  Put  a  piece  of  straw  into  a  little  sulphuric  acid, 
and  show  its  decomposing  power,  as  it  charrs  or  changes 
the  sta-aw  into  carbon.  Explain  that,  although  sul- 
phuric acid  exists  in  plaster  of  Paris,  alum,  Glauber 
salts  and  Epsom  salts, — all  of  which  should  be  exhibited 
to  the  class,  —  they  are  not  possessed  of  its  burning  or 
corrosive  properties.  Add  water,  very  cautiously,  to  a 
portion  of  the  acid  placed  in  a  tea-cup,  and  show  the 
great  heat  produced  by  their  combination.  When  very 
largely  diluted,  let  the  solution  be  tasted,  that  acidity 
may  be  recognized  in  contradistinction  to  the  taste  of 
alkalies.  Add  a  little  sulphuric  acid  to  an  infusion  of 
red  cabbage,  showing  that  acids  redden  vegetable  sub- 
stances ;  then  to  the  reddened  solution  add  any  alkali, 
until  the  acid  is  neutralized,  and  the  alkali  is  slightly 
in  excess,  and  show  the  production  of  the  blue  color. 

Next,  add  an  alkali  to  the  infusion  of  red  cabbage, 
and  show  the  change  effv3cted  by  alkalies.  Then  neu- 
tralize the  alkali  by  the  addition  of  sulphuric  acid,  and 
as  soon  as  the  acid  is  sliglitly  in  excess  the  bright  red 
col*«r  will  be  again  produced. 


ya  APPENDIX. 

14.  Ignite  a  very  small  piece  of  phosphorus  in  the 
air  ;  the  white  fumes  are  phosphoric  acid.  Fill  a  saucer 
with  water,  let  a  little  piece  of  cork  float  upon  it ;  place 
upon  the  cork  a  minute  piece  of  phosphorus,  ignite  it, 
and  invert  over  it  a  large  tumbler-glass,  or  a  wide-mouth 
glass  bottle.  It  is  at  once  filled  with  dense  white  fumes, 
which  are  phosphoric  acid.  After  a  while  the  fumes 
disappear,  the  water  has  dissolved  the  phosphoric  acid, 
and  the  glass  only  contains  the  nitrogen  which  entered 
into  the  composition  of  the  air.  Phosphorus  must  be 
used  very  cautiously,  and  always  cut  under  water ;  and 
it  should  never  be  handled,  as  the  heat  of  the  skin  is 
sufficient  to  ignite  it.  It  should  be  always  taken  up 
with  a  pair  of  tweezers,  or  small  forceps. 

15.  Put  a  few  pieces  of  limestone,  or  of  the  common 
soda  of  the  shops,  into  a  tall  glass  (Fig.  2),  and  pour 
thereon  a  little  dilute  muriatic  acid.  Effervescence  com- 
mences with  the  evolution  of  carbonic  acid  gas.  Put 
into  the  glass  an  ignited  taper  ;  it  is  extinguished,  but 
the  gas  is  not  inflamed  like  hydrogen.  Then  make  the 
gas  in  a  Florence  flask  (Fig.  6) ,  by  the  introduction  of 
the  lime  and  dilute  acid,  and  collect  it  in  bottles  in  the 
same  way  as  chlorine  was  collected,  because  it  is  much 
heavier  than  the  atmosphere.  Put  the  lighted  taper 
into  an  empty  glass  (Fig.  10) ,  and  pour  upon  it  car- 
bonic acid  gas  from  a  bottle  or  another  glass.  The  ta- 
per is  extinguished,  as  though  water  had  been  poured 
upon  it,  instead  of  an  invisible  gas.  Light  a  common 
candle  (Fig.  11)  and  pour  upon  it  the  gas  contained  in 
an  apparently  empty  tumbler ;  the  flame  of  the  candle 


APPENDIX.  •  93 

is  instantly  extinguished.  Now,  while  the  wick  contin- 
ues red,  plunge  the  candle  into  a  bottle  of  oxygen,  and 
it  will  be  again  enkindled  into  a  flame. 

16.  Introduce  a  piece  of  kindled  charcoal  into  a  bot- 
tle of  oxygen  gas.  When  the  charcoal  no  longer  burns, 
which  it  will,  for  a  short  time,  with  gieat  brilliancy, 
put  a  lighted  taper  into  the  bottle,  and  the  presence  of 
carbonic  acid  gas  will  be  recognized  by  its  being  instantly 
extinguished. 

17.  To  form  humic  acid,  the  teacher  will  dissolve  a 
little  common  soda  in  water,  boil  the  solution  upon 
finely-powdered  peat,  or  rich  dark  soil.  Pour  off  the 
solution  when  it  has  become  clear.  The  soda  has  united 
with  the  humic  acid.  Now  add  a  little  diluted  muriatic 
acid ;  the  muriatic  acid  will  combine  with  the  soda, 
forming  muriate  of  soda,  which  remains  in  the  solution, 
and  the  humic  acid,  being  liberated,  falls  down  in  brown 
flakes.  This  humic  acid  consists  of  carbon  and  water 
only,  or  of  carbon,  hydrogen  and  oxygen. 

18.  Mix  a  little  flour  with  water  into  a  dough  ;  put 
it  into  a  large  tumbler  full  of  water,  over  the  top  of 
which  is  tied  a  piece  of  fine  muslin.  Shake  it  a  while, 
then  pour  off  the  water,  carrying  with  it  the  starch  ; 
add  fresh  water  until  it  comes  away  quite  clear.  Let 
the  water  containing  the  starch  stand  a  while,  so  that 
the  starch  may  settle  to  the  bottom  and  be  collected. 
Then  exhibit  the  gluten  remaining  after  all  the  starch 
has  been  thus  washed  away. 


94-  •  APPENDIX. 

19.  The  following  table  should  be  printed  on  paste- 
board, and  suspended  on  the  wall  of  the  school-room,  or 
written  legibly  on  the  black-board  : 

72  lbs.  of  woody  fibre  contain  carbon  36  lbs.,  water  36  lbs. 
81  lbs.  of  dry  starch  or  gum  contain  carbon  36  lbs.,  water  45  lbs. 
85^  lbs.  of  loaf-sugar  contain  carbon  36  lbs.,  water  49^  lbs. 
63  lbs.  of  humic  acid  contain  carbon  36  lbs.,  water  27  lbs. 

Let  the  teacher  direct  attention  to  the  fact  that  these 
very  different  appearing  substances  all  contain  the  same 
elements ;  that  in  the  quantities  designated  they  all 
contain  thirty-six  pounds  of  carbon,  but  that  the  hydro- 
gen and  oxygen,  in  the  form  of  water,  differs  in  quantity 
in  each. 

20.  Let  the  teacher  remark  the  difference  between 
elementary  and  compound  bodies.  Compound  bodies- 
can  be  divided  into  two  or  more  elementary  bodies. 
Thus  starch  may  be  divided  into  carbon,  hydrogen  and 
oxygen  ;  but  these  elements  cannot  be  again  subdivided, 
or  decomposed  into  other  bodies.  Water  is  a  compound 
body,  containing  hydrogen  and  oxygen.  Carbonic  acid 
contains  carbon  and  oxygen.  The  air  we  breathe  con- 
tains nitrogen  and  oxygen.  He  may  add  to  these  illus- 
trations ad  libitum, 

21.  (See  Fig.  15.)  Explain  the  meaning  of  the  word 
carbonaceous,  and  refer  again  to  the  organic  and  inor- 
ganic forms  of  matter. 

22.  The  words  dissolve  and  solution  should  be  practi- 
cally illustrated.     Dissolve  some  salt  and  sugar  in  a 


APPENDIX.  95 

tumbler  of  water.  They  have  disappeared.  What  has 
become  of  themi  They  are  held  in  solution  in  the 
water.  Now  let  the  water  be  boiled  down,  or  slowly 
evaporated,  and  the  salt  and  sugar  will  become  again 
visible  in  the  form  of  crystals. 

Dissolve  in  water  as  much  alum  as  it  can  take 
up.  When  the  water  can  dissolve  no  more  it  is  said 
to  be  saturated.  Let  the  solution  of  alum  remain  un- 
disturbed for  a  few  days,  in  a  warm  place,  and,  as  the 
water  is  carried  off  by  evaporation,  the  alum  will  be 
restored  to  the  crystalline  form.  Explain  how  the  soil 
becomes  dry  and  parched,  in  the  hot  weather  of  sum- 
mer, by  this  process  of  evaporation. 

23.  The  tables  on  the  43,  45  and  47  pages,  should  be 
printed  on  a  large  sheet  of  pasteboard,  and  hung  up  in 
the  school-room.  They  will  suggest  many  important 
questions,  and  familiarize  the  class  with  the  facts  they 
contain. 

24.  Explain  the  terms  by  which  chemists  denote  the 
different  kinds  of  saline  substances,  or  of  alkalies  in 
combination  with  acids.  Thus,  when  nitric,  sulphuric, 
muriatic,  carbonic  or  phosphoric  acid,  combine  with  the 
alkali  soda,  they  form  the  mtrate,  sulpha^g,  muriate, 
carbonate  or  phosphoiJe  of  soda.  If  they  combine  with 
lime,  then  we  have  the  nitrate,  the  sulpho/e,  the  muri- 
ate, the  c&Tbonate  or  the  phosphate  of  lime. 

When  the  nitwus  or  sulphurow*  acids  combine  with 
alkalies,  the  salts  formed  are  called  sulphtVe5;  thus  we 
have  the  sulphtYe  of  soda,  or  the  mtrite  of  lime. 


96  APPENDIX. 

When  we  speak  of  the  sulphate  of  soda,  we  mean  a 
substance  called  a  salt,  composed  of  soda,  which  is 
called  the  base,  and  sulphuric  acid.  Hence,  the 
phosphate  of  lime  is  a  salt  containing  lime,  the  base, 
and  phosphoric  acid ;  and  carbonate  of  potash,  a  salt 
containing  potash  as  the  base,  and  carbonic  acid. 

25.  In  addition  to  the  four  elementary  bodies,  carbon, 
hydrogen,  oxygen  and  nitrogen,  which  constitute  the 
organic  part  of  plants,  some  of  them  also  contain 
small  quantities  of  sulphur,  and  larger  quantities  of 
phosphorus.  These  additional  organic  elements  are 
obtained  from  the  sulphuric  acid  and  phosphoric  acid 
contained  in  the  soil. 

Sulphuric  acid  is  a  combination  of  sulphur  and  oxy- 
gen. The  plant  decomposes  the  acid,  retaining  a  por- 
tion of  its  sulphur,  and  throwing  off  the  oxygen  with 
which  it  was  combined ;  and  the  same  explanation  may 
be  applied  to  the  phosphorus  some  plants  contain. 

26.  Reference  has  been  made  to  under-draining  wet 
lands ;  we  annex  the  methods  whereby  this  result  may 
be  attained. 

Good  drains  may  be  made  with  small  stones,  as  shown 

in  the  annexed  sectional. 

diagrams.    They  are  very  ' 

effective  if  well  made,  but 

not  so  useful  or  durable 

as  those   constructed  of 

tiles.     The  small  stones 

should  be  covered  by  a 


APPENBIX. 


97 


sod,  or  turf,  the  grass  downwards,  and  the  earth  firmly 
trod  down  over  them. 

Tile-drains  may  be  constructed  of  a  variety  of  forms. 
When  laid  down  the  slopes  of  the  lands,  and  about 
twenty  to  thirty  feet  distant,  tile-tubes  of  a  single  inch 
diameter  will  carry  off  all  the  surplus  water,  unless  it  is 
unusually  abundant.  We  annex  several  forms  of  tiles, 
adapted  for  different  kinds  of  lands,  and  the  mode  of 
their  insertion  in  the  ground. 

1  '         2 

Nos.  1  and  2  are  available 
where  the  quantity  of  water  is 
not  greatly  in  excess ;  and  Nos. 
3,  4  and  5  are  also  applicable 
where  the  surplus  water  is  not 
too  great. 


98  APPENDIX. 

6  No.  6  is  the  common  oval  drain,  de» 

signed  and  adapted  for  very  vret  lands,  or 
for  lands  where  only  a  slight  fall  can  be 
obtained. 

27.  All  fertile  soils  contain  gypsum^ 
Sometimes  it  exists  in  sufficient  quantity 
for  all  the  purposes  of  successful  agricul- 
ture, without  any  artificial  supply  ;  and 
in  localities  near  the  sea-coast  the  sulphate  of  soda  sup- 
plies its  deficiency,  if  any  exists.  But  where  gypsum  is 
naturally  abundant  in  the  soil,  it  is  profitably  scattered 
over  the  manure-heap,  the  stable,  and  the  urine-tank, 
for  the  purpose  of  arresting  the  escape  and  loss  of  the 
volatile  ammonia,  which  it  transforms  into  the  sulphate, 
which  is  not  volatile.  Scattered  also  on  corn  and  potato 
drills,  it  is  very  serviceable  in  arresting  the  ammonia 
which  a  spell  of  dry  weather  causes  to  ascend  from  the 
manure  beneath  the  soil,  and  in  the  form  of  the  sulphate, 
retaining  it  at  the  surface,  ready  to  be  again  carried 
into  the  soil  vdth  the  first  rain  which  falls. 

28.  A  knowledge  of  the  chemical  constituents  (the 
principal  organic  elements)  which  enter  into  the  com- 
position of  urine,  is  of  much  practical  value  to  the  scicD- 
tific  farmer. 

Carbon,  20.0 

Hydrogen,        6.6 

Oxygen,         46.7 

Nitrogen,       26.7 

imo 

In  the  process  of  decomposition  this  substance  unites 


APPENDIX. 


with  water,  forming  carbonate  of  ammonia,  wliich  is 
rapidly  lost  in  the  atmosphere,  unless  absorbed  by  earth, 
peat,  s\\"amp-8oil,  etc.,  or  changed  into  the  nou- volatile 
sulphate  of  ammonia  by  gypsam,  or  sulphuric  acid.  In 
addition  to  the  urea,  and  some  other  organic  matter, 
urine  contains  potash,  soda,  and  phosphatic  salts. 

29.  We  annex  an  analysis  of  100  parts  of  stable  ma- 
nure, dried  at  the  temperature  of  boiling  water. 

1st.  The  organic  part : 

Carbon,     .         .         .         .         . 
Hydrogen,      .... 
Oxygen,     .         .         .         .  '       . 
Nitroo;en,       .... 


Ashes, 


37.40 
5.27 

25.51 
1.76 

30.05 


100.00 
2nd.  Inorganic  components  of  100  parts  of  ashes  : 
Potash,     .         .         .         .         .     3.32^ 

2.73 

Soluble  in 

water. 


OUUU),       .              .             .              .              . 

I.ime,        .... 

.    0.34 

Magnesia,      .        .        .        . 

0.26 

Sulphuric  Acid, 

.     3.27 

Chlorine,        .         .         .         . 

3.16 

Silicia,      .... 

.     0.04, 

Phosphate  of  Lime, 

7.111 

*'         "  Magnesia,     . 

.     2.26 

*'         "  Oxide  of  Iron,   . 

4.68 

Carbonate  of  Lime,    . 

.     9.34 

"         "  Magnesia, 

1.63 

Silicia,      .... 

,  27.01  J 

Insoluble  sand,  etc., 

34.96 

Soluble  in 
^  Hydrochloric 
acid. 


100  APPENDIX. 

By  long  exposure  to  the  air  and  weather,  much  of  the 
most  valuable  portion  of  the  organic  part  of  the  manure 
escapes  into  the  atmosphere,  and  another  considerable 
portion  is  washed  away  and  carried  off.  From  these 
causes  the  soil  is  deprived  of  much  of  the  most  valuable 
and  fertilizing  portion  of  the  manure,  and  hence  the 
crops  are  also  hindered  in  their  growth  and  perfection. 
The  intelligent  farmer  will,  therefore,  protect  his  manure 
from  these  sources  of  loss  ;  and  he  wUl  be  also  enabled, 
by  reference  to  the  tables  already  given,  to  supply  an 
additional  quantity  of  those  substances  which  the  land 
may  need,  in  order  to  insure  the  best  and  most  profit- 
able crops. 

30.  In  the  progress  of  this  work  we  have  had  occasion 
to  refer  to  certain  elementary  bodies,  or  substances, 
whose  combinations  make  up  the  organic  part  of  plants. 
These  elementary  bodies  are  chemically  expressed  by 
definite  characters,  or  symbols,  and,  as  their  use  is  uni- 
versally adopted,  we  have  subjoined  the  symbols  of  all 
the  principal  substances  to  which  reference  has  been 
made. 

31.  In  addition  to  the  symbol,  a  numeral  will  be 
noticed,  called  the  equivalent,  wliich  means  the  com- 
bining number.  Thus  the  symbol  of  Oxygen  is  O  —  its 
equivalent,  or  combining  number,  8  ;  the  symbol  of 
Nitrogen  is  N — its  equivalent,  14.15. 

32.  Bodies,  in  forming  chemical  combinations,  unite 
in  certain  fixed  or  definite  proportions,  and  these  com- 


APPENDIX.  101 

bining  proportions  are  observable  whether  two  elements 
combme  to  form  a  single  compound,  or  half  a  dozen  dif- 
ferent compounds  ;  and  the  successive  combinations  are 
multiples,  or  simple  ratios,  which  may  be  expressed  by 
the  numerals  1,  2,  3,  4,  5,  etc.,  or  1,  1^,  2,  2^,  3,  3^, 
etc. 

33.  In  the  first  order,  it  will  be  seen  that  the  quanti- 
ties expressed  by  2,  3,  4,  etc.,  a^e  multiples  of  the  fir^t  > , 
and  in  the  second  series,  the  quan^itit's;  are>  ,iQpreas^4  ^H 
each  combination  one-half  of  ihe  first.      ,  ,  ,  ,    ,    , ,    ,    , 

The  following  illustrates  the  .cohib-mat'oiis  of  JsitVoJct^n 
and  Oxygen,  and  they  will  be  found  to  follow  the  first 
series  of  numbers;  for,  while  the  Nitrogen  remains 
stationary,  the  Oxygen  in  each  succeeding  combination 
is  a  multiple  of  8,  its  equivalent  number. 

COMBINATIONS   OF   NITROGEN  AND   OXYGEN  : 

Nitrous  oxide,  Nitrogen,  (N)  14.15 
Nitric  oxide,  do.  14.15 

Hyponitrous  acid,    do.  14.15 

Nitrous  acid,  do.  14.15 

Nitric  acid,  do.  14.15 

34.  The  annexed  combinations  of  Oxygen  with  lilan- 
ganese  illustrate  the  second  series  of  figures,  wherein 
each  succeeding  number  is  increased  by  the  addition  of 
half  of  the  first,  or  equivalent. 

9=^ 


Oxygen, 

(0)  81 

1 

do. 
do. 

16    2 

24  >3 

do. 

32 

4 

do. 

40 

5 

102 


APPENDIX. 


COMBINATIONS   OF  MANGANESE  AND   OXYGEN  I 

Protoxide  of  Manganese,  {Mn)  27.7  :  Oxygen,  ( O)  8  "^  1 
Sesquioxide  do.  27.7 :        do.         12     1^ 

Peroxide  do.  27.7 :        do.         16  I  2 

Not  yet  discovered  do.  27.7 :        do.         20  [2^ 

Manganic  acid       do.  27.7  :         do.         24     3 

Permanganic  acid  do.  27.7:        do.         28  J  3^ 

It  vkdll  be  seen  that  the  fourth  line  in  the  above  list  is 
qaM^J.ess,  ne  oorafeitiatioii  having  yet  been  discovered  to 
complete  the  series.  That,  a  form  of  matter  exists,  and 
■  ma*^  ^e*,*b^  discovered,  to; fill  the  vacancy,  is  most 
'  p'r'obatfclfe.  ' 

35.  Symbols  and  Equivalents  of  the  Elementary  Sub- 
stances referred  to  in  this  work  : 


NAME. 

SYMBOL. 

EQUIVALENT 

Carbon,  .... 

.    c    .    .    . 

.          6.12 

Hydrogen,   .     .     . 

.     H   ,     .     . 

.          1. 

Oxygen,       .     . 

.     0    .     .     . 

.      8. 

Nitrogen,     .     .     . 

,    N   ,     .     . 

.     14.15 

Potassium  (Kalium),      K    .     . 

.     .     39.15 

Sodium  (Natrium) 

,    .     Na  ,     . 

.     23.3 

Calcium,      .     .     . 

.     Ca.     . 

.     20.5 

.Magnesium,      .     . 

Mg,     . 

.     12.7 

Silicion,  .... 

.     &•    .     . 

.     22.5 

Chlorine,      .     .     . 

.   a  .   . 

.     .     35.42 

Sulphur,       .     . 

.   s  .    . 

.     16.1 

Phosphorus, 

.  p  .    . 

.     15.7 

Iron,   .... 

,     .     Fe  .     , 

.     .     28.0 

Manganese,  .     . 

.     ,     Mn.     , 

.  • .    27.7 

Aluminum,  .     . 

.    Al  ,     , 

.    .    13.7 

APPENDIX.  108 

These  symbols  are,  in  most  instances,  the  first  letter 
of  the  Latin  word  expressing  the  article  named.  But  it 
will  be  seen  in  the  table  that  some  substances  have  a 
small  letter  added  to  the  capital ;  the  necessity  for  this 
addition  is  easily  explained.  The  symbol  of  Carbon  is 
C,  but  Calcium  (the  Latin  word  for  lime)  also  begins 
with  C,  — hence,  to  avoid  all  confusion  in  the  symbols, 
Calcium  is  designated  by  Ca.  In  the  same  manner,  A'' 
is  the  symbol  of  Nitrogen,  and  Na  of  Natrium,  or  Soda. 

36.  Table  of  the  principal  Compound  Bodies  named 
in  this  work  : 

NAME.  BLEMBNTS.  EQUIVALENT.  SYMBOL. 

Sulphuric  acid, S   16.1    .  O  24  .  =  40.1    .  .  503 

Nitric  acid,     N  14.15  .  O  40  .  =  54.15  .  .  NOh 

Hydrochloric  (Muriatic)  acid,  CI  35.42  .Hl.=  36.42  .  .  HCl 

Phosphoric  acid, P  31.34  .0  40  .  =  71.4    .  .Pi  Oh 

Carbonic  acid, C     6.12  .0  16  .  =  22.12  .  .  CO2 

Water, HI,     .  O    8  .  =   9.     ,  .  HO 

In  examining  the  symbols,  there  will  be  seen  appended 
to  some  of  them  small  figures  ;  thus,  O3.  The  use  of 
those  figures  is  important,  and  should  be  remembered. 
Let  us  examine  the  first  symbol,  that  of  Sulphuric  acid. 
"We  find  its  elements  to  be  Sulphur  (-S)  16.1,  which,  on 
reference  to  the  first  table  of  symbols,  is  seen  to  be  its 
equivalent  or  combining  number ;  and  Oxygen  (0)  24, 
reference  to  the  table  of  symbols  gives  8  as  the  combining 
number  of  Oxygen ;  hence,  in  the  number  24  we  find 
three  times  8,  or  3  equivalents  of  Oxygen.  Then  we 
learn  that  to  form  Sulphuric  acid  one  equivalent  of 
Sulphur  is  combined  with  three  equivalents  of  Oxygen, 
and  the  symbol  &0.^  indicates  that  combination. 


104  APPENDIX. 

The  symbol  of  Phosphoric  acid  is  PgO^ ;  hence,  there 
are  two  equivalents  of  Phosphorus  combined  with  five 
equivalents  of  Oxygen  requisite  to  make  Phosphoric  acid. 
An  equivalent  of  Phosphorus  is  15.7,  multiplied  by  2 
gives  31.4  ;  an  equivalent  of  Oxygen  is  8,  multiplied  by 
5  gives  40  ;  and  31.4  added  to  40  =  71.4,  which  is  the 
equivalent  of  Phosphoric  acid,  as  expressed  by  its  sym- 
bol P2O5. 

NAME.  BASE.   ACID.      EQUIVALENT,      SYMBOL. 

Sulphate  of  Lime, 1  eq.  -f   1    .   .   .  68.6  .   .  CaO,  SO3 

"  "  as  gypsum,  with  2  eq.  of  water  18    .86.6.   . 

Carbonate  of  Lime  (Marble),     .  1  eq.  -f  1  eq.    .  .  50.62    .  CaO^  CO2 
Sulphate  of  Soda,  .   .   .   .   .   .   .  1  eq.  -f  1  eq.    .   .  71.4  .   .  NaO,  SO3 

«  "    in  crystals,  with  10  eq.  of  water  90. 161.4  .   . 

Nitrate  of  Soda, 1  eq.  -f  1  eq.  .   .  85.45  .   .  NaO,  NOb 

Chloride  of  Sodium  (com.  salt),   1  eq.  -f  1  eq.  of  C^  58.72  .   .  NaO 
Nitrate  of  Potassa  (saltpetre),  .  1  eq.  -|-  1  eq.  .    101.3    .   .  KOy  NOb 
Carbonate  of  Magnesia,  .   .   .   .  1  eq.  +  1  eq.  .   .  42.82  .   .  MgO,  CO^ 
Sulphate  of  Ammonia,    .   .   .   .  1  eq.  -f  1  eq.  .   .  66.25  .   .  NHi  O,  503 
Nitrate  of  (oxide  of)  Ammonia,  1  eq.  -f- 1  eq.  .   .  80.3    .   .  Hi  NO^NOb 
Muriate  of  Ammonia, 1  eq.  -f- 1  eq.  .   .  53.57  .   .  H\N^  HCl 

The  teacher  should  analyze  and  explain  the  above  sym- 
bols, showing  his  class  the  value  of  the  numerals,  and 
the  part  they  play  in  the  formation  of  the  articles  they 
represent.  Thus,  Sulphate  of  Lime  is  composed  of  Ca  0 
and  S0^\  Ca,  the  symbol  of  Calcium  (20.5),  and  O, 
the  symbol  of  Oxygen  (8) ,  represent  that  combination 
called  Oxide  of  Calcium ;  one  equivalent  of  this  Oxide 
of  Calcium  is  combined  with  one  equivalent  of  Sulphuric 
acid;  S,  the  symbol  of  Sulphur  (16.1),  and  Oy,  the 
symbol  of  Oxygen  (8),  multiplied  by  3.  Now,  we  may 
show  the  formation  of  the  Sulphate  of  lime,  and  the 


APPENDIX.  105 

mode  of  obtaining  its  equivalent  number,  by  the  follow- 
ing diagram  : 

1  eq.  of  Oxide  of  Calcium  contains  C  Ca  .  1  eq.  20.5 
\0    .leq.    8.0 


Sulphate  of  Lime, 


1  eq.  of  Sulphuric  acid  contains     <  S    .  1  eq.  16.1 


lOi  .3  eq.  24.0 
The  equivalent  number  of  Sulphate  of  Lime, 68.6 

37.  Composition  of  Starch,  Gum  and  Sugar  : 

Starch, Cu  Hio  Oio 

Gum  and  Cane  Sugar,  C12  Hn  On 

Sugar  of  Milk,  .     .     .  Cu  H12  Ou 

Grape  Sugar,     .     .     .  C12      14  u 

The  above  table  shows  that  while  in  all  the  articles 
named  the  Carbon  remains  the  same,  they  are  almost 
identical  in  their  chemical  constitution,  —  the  only  dif- 
ference being  the  slight  addition  of  water,  or  the  elements 
of  water  ;  this  will  be  more  readily  apparent  from  the 
following  view  : 

Starch, 12  C  +  10  water. 

Cane  Sugar  and  Gum,  12  C  -j-  10  water  -}-  1  water. 

Sugar  of  Milk,     .     .  12  C  +  10  water  +  2  water. 

Grape  Sugar,  .     .     .  12  C  -|-  10  water  4-  4  water. 

Hence,  for  the  same  number  of  equivalents  of  Carbon, 
Starch  contains  of  water  or  its  elements  10  equivalents ; 
Cane  Sugar  and  Gum,  11  equivalents ;  Sugar  of  Milk, 
12  equivalents  ;  and  Grape  Sugar,  14  equivalents. 

38.  Cultivation  is  the  economy  of  force  ;  while  science 
teaches  us  the  simplest  means  of  obtaining  the  greatest 
results  with  the  smallest  expenditure  of  power,  and  the 
consequent  development  of  the  largest  amount  of  force. 


106  APPENDIX. 

39.  A  tribe  of  hunters  confined  to  a  limited  space  can- 
not increase  in  number  beyond  a  fixed  and  early  attained 
point.  Respiration  demands  Carbon,  and  the  savage 
must  obtain  the  Carbon  he  consumes  in  respiration  from 
the  flesh  of  the  animals  he  eats.  The  animals  collect 
from  the  vegetable  products  the  constituents  of  their 
organs  and  blood,  and  these  are  yielded  to  the  savage 
who  lives  alone  by  the  chase,  unaccompanied  by  those 
non-azotized  substances  which,  during  the  life  of  the 
animals,  served  to  support  the  respiratory  process. 
Whenever  man  is  confined  to  a  flesh  diet,  the  Carbon  of 
the  flesh  and  blood  must  take  the  place  of  Starch  and 
Sugar,  those  great  sources  of  the  supply  of  Carbon  to 
the  grain-eating  animals  and  civilized  man. 

40.  Fifteen  pounds  of  flesh  contain  no  more  Carbon 
than  four  pounds  of  Starch.  A  savage  who  could  main- 
tain life  for  a  given  number  of  days  with  one  animal, 
and  an  equal  weight  of  starch,  if  confined  to  flesh  alone, 
would  require  five  such  animals  in  the  same  number  of 


41.  From  the  consideration  of  these,  and  many  simi- 
lar facts,  how  full  of  interest  becomes  the  connection 
between  agriculture  and  the  multiplication  of  the  human 
family '  Agriculture  has  but  one  object,  and  that  is,  to 
produce  from  the  smallest  possible  space  the  largest  pos- 
sible amount  of  nutritious  and  life-sustaining  substances. 

42.  A  cow,  or  a  sheep,  eats  almost  uninterruptedly 
from  sunrise  to  sunset  (whilst  at  large  in  the  meadow) , 
and  yet  it  wastes  nothing  of  the  amount  it  consumes ; 


APPENDIX.  107 

for  all  that  is  not  demanded  for  the  mere  supply  of  the 
waste  of  its  body  in  the  maintenance  of  life  is  con- 
verted into  organized  tissues ;  the  excess  of  blood  made 
is  transformed  into  cellular  and  muscular  substance. 

43.  The  stall-fed  animal  eats,  and  reposes  merely  for 
the  purpose  of  digestion.  It  consumes,  in  the  form  of 
nitrogenized  substances,  much  more  food  than  is  requisite 
to  supply  the  waste  effected  by  the  vital  processes ;  and 
at  the  same  time  it  eats  much  more  non-nitrogenized  food 
than  is  required  for  respiration  and  the  production  of 
animal  heat.  The  excess  of  Carbon  thus  taken  up  by 
the  animal  is  not  converted  into  muscle  (lean  meat), 
but  is  transformed  into  fat,  —  a  substance  which,  in  the 
natural  state,  is  only  found  in  small  amount  in  the  brain 
and  nerves. 

44.  The  flesh  of  wild  animals  is  almost  wholly  devoid 
of  fat,  while  the  flesh  of  stall-fed  animals  is  covered  with 
a  thick  layer  of  that  substance.  But,  if  the  stall-fed 
animal  is  permitted  to  go  at  large,  or  is  put  to  hard 
labor,  the  excess  of  fat  soon  disappears. 

45.  A  horse  can  be  kept  in  a  perfectly  good  condition 
if  he  can  obtain  as  food  fifteen  pounds  of  hay  and  four 
and  a  half  pounds  of  oats,  daily. 

46.  A  hog  fed  with  highly  nitrogenized  food  makes 
flesh  (lean  meat  or  muscle) ,  but  if  fed  upon  diet  con- 
taining much  starch  (Carbon)  it  acquires  little  flesh, 
with  a  great  excess  of  &t.    It  i»  because  apples  contain 


108  APPENDIX. 

sugar  (Carbon)  that  they  are  so  useful  in  fattening  hogs, 
or  other  stock. 

47.  Every  article  of  food  may  be  divided  into  two 
classes,  nitrogenized^  and  non-nitrogenized ;  the  former 
alone  are  capable  of  transformation  into  blood,  and  may 
be  called  the  nutritious  elements.  Amongst  the  most 
important  of  these  are  vegetable  fibrine,  vegetable  albu- 
men, animal  flesh  and  animal  blood. 

48.  The  non-nitrogenized  substances  v^hich  enter  into 
the  food  of  man  and  beast  may  be  designated  the  cfe- 
ments  of  respiration;  amongst  these  are  fats,  starchj 
gum,  and  sugar. 

END. 


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YA  CfcbOS 


667876 


UNIVERSITY  OF  CALIFORNIA  UBRARY 


